gui, man, authors: Update docs, translations, and contributors

AUTHORS

@@ -300,6 +300,7 @@ Stefan Kuntz (Stefan-Code) <[email protected]> <[email protected]>
 Stefan Tatschner (rumpelsepp) <[email protected]> <[email protected]> <[email protected]>
 Steven Eckhoff <[email protected]>
 Suhas Gundimeda (snugghash) <[email protected]> <[email protected]>
+Sven Bachmann <[email protected]>
 Syncthing Automation <[email protected]>
 Syncthing Release Automation <[email protected]>
 Taylor Khan (nelsonkhan) <[email protected]>