Rename enrich-processor to ingest-processor, pt 3

[shainaraskas]

docs-builder doesn't handle moves from one standalone toc to another gracefully, so we need a multi-step process

1. make a copy of the docs Step 1 of renaming processor docs path #149537
2. wire up the copy in docs-builder (this unhides the docs, leaving two parallel sets) wire up replacement processor reference  docs-builder#3367
3. copy over any changes from the old docs set, update xrefs, redirect (leaving a stub)
4. delist the old docs in docs-builder
5. clean up stub

this is step 3.