Unflatmap community.general (#5461)

* Move files.

* Update imports and references.

* Move wrongly placed files.

* Reverse redirects, deprecate long → short name redirects.

* Simplify contribution guidelines for new modules.

* Rewrite BOTMETA.

* Add changelog fragment.

* Fix ignore.txt files.

CONTRIBUTING.md

@@ -112,17 +112,7 @@ Creating new modules and plugins requires a bit more work than other Pull Reques
    - Make sure that new plugins and modules have tests (unit tests, integration tests, or both); it is preferable to have some tests
      which run in CI.
 
-4. For modules and action plugins, make sure to create your module/plugin in the correct subdirectory, and add a redirect entry
-   in `meta/runtime.yml`. For example, for the `aerospike_migrations` module located in
-   `plugins/modules/database/aerospike/aerospike_migrations.py`, you need to create the following entry:
-   ```.yaml
-       aerospike_migrations:
-         redirect: community.general.database.aerospike.aerospike_migrations
-   ```
-   Here, the relative path `database/aerospike/` is inserted into the module's FQCN (Fully Qualified Collection Name) after the
-   collection's name and before the module's name. This must not be done for other plugin types but modules and action plugins!
-
-   - Action plugins need to be accompanied by a module, even if the module file only contains documentation
+4. Action plugins need to be accompanied by a module, even if the module file only contains documentation
    (`DOCUMENTATION`, `EXAMPLES` and `RETURN`). The module must have the same name and directory path in `plugins/modules/`
    than the action plugin has in `plugins/action/`.
 

changelogs/fragments/unflatmap.yml

@@ -0,0 +1,8 @@
+major_changes:
+  - "The internal structure of the collection was changed for modules and action plugins.
+     These no longer live in a directory hierarchy ordered by topic, but instead are now all in a single (flat) directory.
+     This has no impact on users *assuming they did not use internal FQCNs*. These will still work, but result in deprecation warnings.
+     They were never officially supported and thus the redirects are kept as a courtsey, and this is not labelled as a breaking change.
+     Note that for example the Ansible VScode plugin started recommending these internal names. If you followed its recommendation,
+     you will now have to change back to the short names to avoid deprecation warnings, and potential errors in the future as
+     these redirects will be removed in community.general 9.0.0 (https://github.com/ansible-collections/community.general/pull/5461)."