With https://github.com/elastic/elasticsearch/pull/81870, the Azure, GCS, and S3 repository types have separate, dedicated pages in the Elasticsearch guide. For consistency, this PR creates separate pages for the shared file system, read-only URL, and source-only repository types.
Related changes:
- Adds redirects to the plugins docs
- Fixes a few breaking changes that refer to the Azure, GCS, and S3 repositories as plugins.
Co-authored-by: Adam Locke <adam.locke@elastic.co>
