HLRC: remove duplication from ascii docs

[pgomulka]

there is a way to decrease duplication when writing the documentation for HLRC

Things to fix:

• migration API - once commited HLRC: migration api - upgrade #34898
• bulk API - mostly done by @nik9000 in HLRC: DRY up remaining CRUD docs #34925, small improvements in Docs: HLRC: refactor bulk, migrate and reindex apis #35413
• reindex API - improvments in Docs: HLRC: refactor bulk, migrate and reindex apis #35413

see #34925

[elasticmachine]

Pinging @elastic/es-core-infra

[nik9000]

I think it might be worth renaming this issue an using it to track those DRY-ing up tasks.