BELATED: Add changelog and add changes for v1.1

CHANGELOG.md

+# Changelog
+
+## 1.1
+Comment Feature:  
+* Interaction via WebSockets  
+* Voting on comments by participants  
+* New attributes: read, favorite, correct  
+* Search function  
+* Sorting and filtering  
+* Presentation mode with color indication for participants  
+* Threshold to hide negative comments from participant and lecturer  
+
+Improvements:  
+* Add Progressive Web App functionality for a 'native app' feeling  
+* Theme Manager with 4 Themes to chose from  
+* Designimprovements  
+
+**This version is brought to you by:**  
+Project management: Klaus Quibeldey-Cirkel  
+Lead programming: Tom "tekay" Käsler, Lukas Mauß