Update index.de.json

One single suggestion for improvement. 
And I would like to verify the rest of this translation as a native speaker.
Update index.pl.json
Update index.cs.json

Translated missing parts (sect1_notavail, sect6_mailinglist), minor corrections
Merge pull request #116 from googl1/patch-1

Update index.de.json
Merge pull request #119 from Theon144/master

Update index.cs.json
Merge pull request #118 from the0neyouseek/master

HTML5 Closing style
Merge pull request #117 from private0x0a/master

Update index.pl.json
Mailing list update to index.nn_NO.json.
Fixed a typo.
Mailing list update to index.nb_NO.json.
Yet another typo, sorry!
Merge pull request #120 from chinatsun/patch-1

Mailing list patch to nn_NO and nb_NO translations
Fix a little typo.
Merge pull request #122 from leeroy2098/master

Fix a little typo.
Added the email text
Merge pull request #123 from pakatsui/patch-2

Added the email text
Added the download text
Merge pull request #124 from pakatsui/patch-3

Added the download text
Fixed minor bug
Merge pull request #125 from pakatsui/patch-4

Fixed minor bug