Make examples in examples.md more complete so that they can work

[armchairancap]

Imports are assumed to be too simple to mention, I suppose, but people who know what to import probably don't need to look at those examples...

runtime_config = RuntimeConfigurationObject()

# This types are all hardcoded types needed to decode metadata types
runtime_config.update_type_registry(load_type_registry_preset(name="core"))

# Decode retrieved metadata from the RPC
metadata = runtime_config.create_scale_object(
    'MetadataVersioned', data=ScaleBytes(response.get('result'))
)
metadata.decode()

Of course, I get NameError: name 'response' is not defined. How is this supposed to work?

Okay, let's try the next one:

call = runtime_config.create_scale_object(
    "Call", metadata=metadata
)

Ugh, no metadata... Let's try the 3rd example further below

>>> system_pallet = metadata.get_metadata_pallet("System")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'metadata' is not defined

Okay, that doesn't work either.

Am I the only one who thinks these examples are very hard to try?

Also, in the first example, I wonder what response can there be when there's no connection to anywhere?
I know in pre-V14 that may have been necessary for online presets, but they're not even used (and if they are they should be included in this example).
I'm not even sure this example is how one is supposed to use this library these days...

metadata = runtime_config.create_scale_object(
    'MetadataVersioned', data=ScaleBytes(response.get('result'))
)

# Add the embedded type registry to the runtime config
runtime_config.add_portable_registry(metadata)

Can someone provide a full working example for Encode a Call so that we can move on to other examples, none of which can be followed because of that confusing first example...

If a metadata V14 JSON can be loaded from file or obtained from substrate RPC, that would simplify that example and make it useful.

It'd be best to create a PR to examples.md so that people don't have to find this discussion to figure it out, but I'm not creating a GH issue for this because I may be wrong and it's perfectly documented as-is...