Add docs page for `consul intention list` command

[jkirschner-hashicorp]

We have a CLI command for which there is currently no docs page: consul intention list. This page should follow the same format as similar CLI Command pages.

For context of how this was discovered, see #12004 (comment)

[blake]

The docs page for this command was added in #9468, but hidden from the menu nav in #10180. The command can be re-added to the menu by removing line 301.

consul/website/data/commands-nav-data.json

Lines 298 to 302 in 0913644

	{
	"title": "list",
	"path": "intention/list",
	"hidden": true
	},