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>

nw/dialogs/about.py

@@ -181,6 +181,7 @@ class GuiAbout(QDialog):
                 ("Français", "Jan Lüdke (jyhelle)"),
                 ("Norsk Bokmål", "Veronica Berglyd Olsen"),
                 ("Português", "Bruno Meneguello"),
+                ("简体中文", "Qianzhi Long"),
             ])
         )