* Migrate migration docs from 6.0 to 7.0
Since we only keep one version of migration docs and master is now on 7.0, we
should migrate these so breaking changes can be added in the right place.
* Remove release notes as well
They link to the migration guides, so they have to go.
* Add placeholder notes for 7.0 so doc build is happy
The collect_payloads parameter of the span_near query was previously
deprecated with the intention to be removed. This commit removes this
parameter.
Relates #20385
Removes the More Like This API, users should now use the More Like This query.
The MLT API tests were converted to their query equivalent. Also some clean
ups in MLT tests.
Closes#10736Closes#11003