Rename package from 'nw' to 'novelwriter' (#868)

* Rename nw folder to novelwriter
* Rename nw to novelwriter in auxiliary files
* Rename nw to novelwriter in main app source
* Rename nw to novelwriter in tests
* Make setup script for pdf docs less spammy

novelwriter/assets/themes/syntax/grey_dark.conf

@@ -0,0 +1,25 @@
+[Main]
+name       = Grey Dark
+author     = Veronica Berglyd Olsen
+credit     = Veronica Berglyd Olsen
+url        = https://github.com/vkbo/novelWriter
+license    = CC BY-SA 4.0
+licenseurl = https://creativecommons.org/licenses/by-sa/4.0/
+
+[Syntax]
+background     =  54,  54,  54
+text           = 200, 200, 200
+link           = 200, 200, 200
+headertext     = 225, 225, 225
+headertag      = 225, 225, 225
+emphasis       = 200, 200, 200
+straightquotes = 200, 200, 200
+doublequotes   = 200, 200, 200
+singlequotes   = 200, 200, 200
+hidden         = 150, 150, 150
+keyword        = 225, 225, 225
+value          = 200, 200, 200
+spellcheckline = 200,  46,   0
+errorline      =  46, 200,   0
+replacetag     = 225, 225, 225
+modifier       = 225, 225, 225