6db244abb8
Docs: adds legacy topics (#69898)
* adds legacy topics
* moves legacy and adds deprecation note
* Merge branch 'alerting-docs-support-escalations' of https://github.com/grafana/grafana into alerting-docs-support-escalations
* adds description
* fixes relrefs
* removes relrefs
* removes relrefs
* fixes links
* Adds description frontmatter
* fixing typo
* adds frontmatter
* fix spelling error
(cherry picked from commit be196a4ad0)
Co-authored-by: brendamuir <100768211+brendamuir@users.noreply.github.com>