add language support (Simplified Chinese - initial version) (#817)

* add translator's name in about dialog

* add new CN.ts

* Update nw_zh_CN.ts

* inital version (CN)

* add project_zh_CN.json

* Update project_zh_CN.json

* Revert changes to otherlanguage files

* Change case of first character in 'novelWriter' in Chinese translation

* Update about.py

Change the entry "Simplified Chinese" from English the local name of the language

Co-authored-by: Veronica Berglyd Olsen <1619840+vkbo@users.noreply.github.com>

novelWriter.pro

@@ -34,4 +34,6 @@ TRANSLATIONS += \
     i18n/nw_en_US.ts \
     i18n/nw_fr.ts \
     i18n/nw_nb_NO.ts \
-    i18n/nw_pt.ts
+    i18n/nw_pt.ts \
+    i18n/nw_zh_CN.ts
+