Updated nl.json

I ‘m not familiar with Github and pull requests but I have updated the nl.json file for Mailspring.
Compared it with the en.json and copied the missing parts, translated of course, to the nl.json file which I downloaded from Github.
Some items in the current Mailspring version were not translated yet and some items were updated by me for more consistency.
Hope this helps.
If it must be added to Github instead, please tell me how.

Best regards
Jeroen

nl.json.txt (74.0 KB)