Test Cases (#70)

* Create general.md

* Rename general.md to TCgeneral.md

* Create TCaccountmanager.md

* Create TCtabsAndSplits.md

* Create TCchatting.md

* Create TCemotes.md

* Create TCchannelNavigation.md

* Create TCusernameTabbing.md

* Create TChighlighting.md

* Create TCappearanceSettings.md

* Create TCchatWindowNavigation.md

* Create TCchatterinoFeatures.md

docs/tests/TCappearanceSettings.md

@@ -0,0 +1,11 @@
+* change theme
+* change font size
+* test red line (last message)
+* timestamp settings 
+  * disable timestamps
+  * enable
+  * show seconds
+  * use 12 hour format (am/pm)
+* Display messages with message seperator
+* rescale the window
+* test "rainbow color"-option