Update README.md

Updated

README.md

@@ -53,11 +53,10 @@ Local Storage and Session Storage is stored in the AppData folder:
 - macOS: `~/Library/Application Support/draw.io`
 - Windows: `C:\Users\<USER-NAME>\AppData\Roaming\draw.io\`
 
-Neither Open-source, nor open-contribution
-----------------------------------
+Not open-contribution
+---------------------
 
-draw.io is not open source software. The complete source code required to build the app from scratch is not available.
-draw.io is also closed to contributions.
+draw.io is closed to contributions.
 
 The level of complexity of this project means that even simple changes 
 can break a _lot_ of other moving parts. The amount of testing required