Documented the new ND_DEFAULTLANGUAGE variable

[b4too]

Just a quick add to the config documentation cf https://github.com/methatronc/website/blob/4316f308e83b6a353db7fe35f640411fe5c5f8a0/content/en/docs/Usage/configuration-options.md?plain=1#L75

[deluan]

Ops, good catch! Thanks for this. Just changed the text a bit to avoid having URLs in the table, which makes it even more unreadable :P

[b4too]

My bad, much better that way indeed :) The clearer the better !