Provide better documentation on how the config glob pattern works

[idanov]

Whilst issue #1363 raises more fundamental issues about the glob paths used by the configuration loader classes being tightly coupled with the low level context object, as an interim solution we should better document what actually happens because it's currently not very clear in the docs.

kedro/kedro/framework/context/context.py

Line 356 in e78990c

conf_catalog = self.config_loader.get("catalog*", "catalog*/**", "**/catalog*")

Looking for this information in the docs I checked the following places:

1. configuration.md
   It is sort of present here, but not really comprehensive. We could also do a better job describing the thinking and relationship of AbstractConfigLoader

2. kedro.config.ConfigLoader
   It's sort of in the docstring here, but not really comprehensive. We could make it very clear for readers.

We should also make sure we use word 'glob' in the header it's easily retrievable / search indexed / linkable

[noklam]

The ConfigLoader docstring maybe a good place for mentioning the default.