Based on checking logs, and my own personal needs I added more categories of keywords to pgdoc.link:

• environment variables, like: PGHOST
• config file names, like: pgpass
• functions from some contrib modules, like: akeys, or cube_ll_coord
• various keyword-like functions (?), like: current_user. This happened thanks to bug report by Benjie Gillam

This brought the total number of known keyword to 2410.

As a side note – while I generally like PostgreSQL docs, state of contrib module documentation is …, well, challenging. Every doc has its own approach to listing stuff. That was “fun" to work on, and it's the main reason why I'm sure not all functions/modules are handled. If you will notice something that isn't – please let me know, I'll do my best to add it.