plpgsql_check extension is almost complete now. This extension is available on all environments and for all supported Postgres releases. It is probably too big to be part of contrib, but I think so it can be referenced in https://www.postgresql.org/docs/current/plpgsql-development-tips.html chapter.
What do you think about it?
Without making any valuation on this particular tool, I think we should be very very careful and restrictive about putting such links in the main documentation.
The appropriate location for such references are in the product catalog on the website and on the wiki. (I'd be happy to have a link from the docs to a generic "pl/pgsql tips" page on the wiki, though, if people would think that helpful -- because that would be linking to a destination that we can easily update/fix should it go stale)
