Fix up according to notes, update versions command for 5.7

Signed-off-by: Dj Walker-Morgan <[email protected]>

Author: djw-m

product_docs/docs/pgd/5.6/planning/limitations.mdx

@@ -99,9 +99,7 @@ versions. Mixed version clusters are not supported for extended periods of time.
 Therefore, once an PGD cluster upgrade has begun, you should complete the whole
 cluster upgrade as quickly as possible.
 
-We don't support running mixed versions of PGD except during an upgrade, and we
-don't support clusters running mixed versions even while being upgraded, for
-extended periods.
+We don't support running mixed versions of PGD except during an upgrade, and we don't support clusters running mixed versions even while being upgraded, for extended periods.
 
 For more information on rolling upgrades and mixed versions, see [Rolling upgrade considerations](/pgd/latest/upgrades/manual_overview#rolling-upgrade-considerations).
 

product_docs/docs/pgd/5.6/upgrades/manual_overview.mdx

@@ -59,18 +59,14 @@ nodes are at the newer release. There must be no more than two versions of the
 software running at the same time. An upgrade must be completed, with all nodes
 fully upgraded, before starting another upgrade. 
 
-Where additional caution is required to reduce business risk, more time may be
-required to perform an upgrade. For maximum caution and to reduce the time
-required upgrading production systems, we suggest performing the upgrades in a
-separate test environment first. 
-
-Don't run with mixed versions of the software for any longer than is absolutely
-necessary to complete the upgrade. You can check on the versions in the cluster
-using the [`pgd show-version`](/pgd/5.6/cli/command_ref/pgd_show-version/)
+Where additional caution is required to reduce business risk, more time may be required to perform an upgrade.
+For maximum caution and to reduce the time required upgrading production systems, we suggest performing the upgrades in a separate test environment first.
+
+Don't run with mixed versions of the software for any longer than is absolutely necessary to complete the upgrade.
+You can check on the versions in the cluster using the [`pgd show-version`](/pgd/5.6/cli/command_ref/pgd_show-version/)
 command. The longer you run with mixed versions, the more likely you are to
-encounter issues, the more difficult it is to diagnose and resolve them.  We
-recommend upgrading in off peak hours for your business, and over a short period
-of time.
+encounter issues, the more difficult it is to diagnose and resolve them.  
+We recommend upgrading in off peak hours for your business, and over a short period of time.
 
 While you can use a rolling upgrade for upgrading a major version of the
 software, we don't support mixing PostgreSQL, EDB Postgres Extended, and EDB

product_docs/docs/pgd/5.7/planning/limitations.mdx

@@ -76,32 +76,19 @@ and current listing.
 
 ## Mixed PGD versions
 
-While PGD was developed to [enable rolling upgrades of
-PGD](/pgd/latest/upgrades) by allowing mixed versions of PGD to operate during
-the upgrade process, we expect users to run mixed versions only during upgrades
-and for users to complete their upgrades as quickly as possible. We also
-recommend that you test any rolling upgrade process in a non-production
-environment before attempting it in production.
-
-When a node is upgraded, it returns to the cluster and communicates with the
-other nodes in the cluster using the lowest version of the inter-node protocol
-that is supported by all the other nodes in the cluster. This means that the
-upgraded node will be able to communicate with all other nodes in the cluster,
-but it will not be able to take advantage of any new features or improvements
-that were introduced in the newer version of PGD. 
-
-That will stay the case until all nodes in the cluster have been upgraded to the
-same newer version.  The longer you run mixed versions, the longer you will be
-without the benefits of the new version, and the longer you will be exposed to
-any potential interoperability issues that might arise from running mixed
-versions. Mixed version clusters are not supported for extended periods of time.
-
-Therefore, once an PGD cluster upgrade has begun, you should complete the whole
-cluster upgrade as quickly as possible.
-
-We don't support running mixed versions of PGD except during an upgrade, and we
-don't support clusters running mixed versions even while being upgraded, for 
-extended periods.
+While PGD was developed to [enable rolling upgrades of PGD](/pgd/latest/upgrades) by allowing mixed versions of PGD to operate during the upgrade process, we expect users to run mixed versions only during upgrades and for users to complete their upgrades as quickly as possible.
+We also recommend that you test any rolling upgrade process in a non-production environment before attempting it in production.
+
+When a node is upgraded, it returns to the cluster and communicates with the other nodes in the cluster using the lowest version of the inter-node protocol that is supported by all the other nodes in the cluster. 
+This means that the upgraded node will be able to communicate with all other nodes in the cluster, but it will not be able to take advantage of any new features or improvements that were introduced in the newer version of PGD.
+
+That will stay the case until all nodes in the cluster have been upgraded to the same newer version.  
+The longer you run mixed versions, the longer you will be without the benefits of the new version, and the longer you will be exposed to any potential interoperability issues that might arise from running mixed versions.
+Mixed version clusters are not supported for extended periods of time.
+
+Therefore, once an PGD cluster upgrade has begun, you should complete the whole cluster upgrade as quickly as possible.
+
+We don't support running mixed versions of PGD except during an upgrade, and we don't support clusters running mixed versions even while being upgraded, for extended periods.
 
 For more information on rolling upgrades and mixed versions, see [Rolling upgrade considerations](/pgd/latest/upgrades/manual_overview#rolling-upgrade-considerations).
 

product_docs/docs/pgd/5.7/upgrades/manual_overview.mdx

@@ -59,18 +59,13 @@ nodes are at the newer release. There must be no more than two versions of the
 software running at the same time. An upgrade must be completed, with all nodes
 fully upgraded, before starting another upgrade.
 
-Where additional caution is required to reduce business risk, more time may be
-required to perform an upgrade. For maximum caution and to reduce the time
-required upgrading production systems, we suggest performing the upgrades in a
-separate test environment first. 
-
-Don't run with mixed versions of the software for any longer than is absolutely
-necessary to complete the upgrade. You can check on the versions in the cluster
-using the [`pgd show-versions`](/pgd/latest/cli/command_ref/pgd_show-version/)
-command. The longer you run with mixed versions, the more likely you are to
-encounter issues, the more difficult it is to diagnose and resolve them.  We
-recommend upgrading in off peak hours for your business, and over a short period
-of time.
+Where additional caution is required to reduce business risk, more time may be required to perform an upgrade. 
+For maximum caution and to reduce the time required upgrading production systems, we suggest performing the upgrades in a separate test environment first.
+
+Don't run with mixed versions of the software for any longer than is absolutely necessary to complete the upgrade. 
+You can check on the versions in the cluster using the [`pgd nodes list --versions`](/pgd/5.7/cli/command_ref/nodes/list/) command.
+The longer you run with mixed versions, the more likely you are to encounter issues, the more difficult it is to diagnose and resolve them.  
+We recommend upgrading in off peak hours for your business, and over a short period of time.
 
 While you can use a rolling upgrade for upgrading a major version of the software,
 we don't support mixing PostgreSQL, EDB Postgres Extended, and