I have been having the same issue — I need to do a lot of offline reading. I am eagerly awaiting the day that it is all put into a convenient PDF format. But for now I just mirror the codex.www.remarpro.com site every now and then, using HTTrack.
The command is:
httrack https://codex.www.remarpro.com wa
It will take a while if you’ve got a slow connection, but you’ll have a nice browsable offline copy of all of the docs in Codex.
–Jesse Taylor