Improved the Norwegian translations

[DandelionSprout]

In particular, I added some strings that were missing from nb.po, in the hopes of alleviating the fact that the Norwegian Bokmål translation is not actually being used on https://www.ntppool.org at the time of writing, thus ensuring that whoever knows how to make that translation go live can do that.

[DandelionSprout]

Having now done nb.po, join.html, configuration.html, and intro.html for the Bokmål translation, are there any more files that are mandatory to translate in order for the Bokmål translation to go live? There's a few more files in https://github.com/abh/ntppool/tree/master/docs/ntppool/en, but they seem to be pretty convoluted and rarely used, so I was hoping to skip those that weren't considered crucial.

[abh]

This should show up on https://web.beta.grundclock.com/en/ in a little bit when the containers have rebuilt, etc. Will you let me know if it looks okay so I can enable it for the production site?

[DandelionSprout]

It seems to be showing up pretty well there.

Upon inspection of the on-site implementation of my translation, I notice ~6 minor grammar errors that I most likely want to correct, and I hope to have enough time to do so in a few hours' time.