docs(alerting): fix broken links due to using shared md files (#105195)
* docs(alerting): fix broken links due to using shared md files
* fix prettier errors
* fix aliased links
(cherry picked from commit a1b1de584c)
* Clarify DS managed rules support only the creation of Mimir and Loki rules
* additional copy changes
* Extend `Manage alerts via Alerting UI` description
* fix capital letter
* further details for `Manage alerts via Alerting UI`