Extension for Ansible redirects

[oraNod]

Fixes #2147 and supercedes #2266

This PR extends the Sphinx reredirects extension to load redirects for Ansible documentation from a toml file. The purpose is to replace the httpd mod_rewrite rules in https://github.com/ansible/docsite/blob/main/ansible/11/.htaccess and https://github.com/ansible/docsite/blob/main/.htaccess in a way that is compatible with ReadTheDocs.

If this PR is accepted and merged, there are two follow on actions:

• Create a robots.txt file to stop crawlers from indexing the generated HTML files. We can put the robots.txt file in the ansible/docsite repo and copy it across as part of the ReadTheDocs build.
• Remove all the existing stub files from this repository. For example, all the files under the docs/docsite/rst/user_guide folder.

[samccann]

LGTM

[oraNod]

@webknjaz / @felixfontein / @gotmax23 Could we please get another round of reviews here? I've added all the redirects to the ReadTheDocs project and this PR is one of the last hurdles in the way of the docs.ansible.com migration. Thanks.

[webknjaz]

Suggested change

	if: env.REDIRECTS == 'true'
	run: >-
	make webdocs EXTRA_TAGS="-t redirects" ANSIBLE_VERSION="${{
	env.PACKAGE_VERSION != 'devel' && env.PACKAGE_VERSION || ''
	}}"
	working-directory: build-directory/docs/docsite
	- name: Build the Ansible community package docs
	if: env.REDIRECTS == 'false'

[oraNod]

@webknjaz I believe this should be conditional based on the inputs. For some builds, such as deploying to gh-pages, you probably don't want to generate redirects.

Also if we remove the condition here, shouldn't we remove the generate-redirects input?