Add notice of deprecation.

Author: Cammymoop

README.md

@@ -1,8 +1,9 @@
-# Lospec Pixel Editor
+# -*DEPRECATED*- Lospec Pixel Editor
 
-This is a browser based software for creating pixel art
+**⚠ The Lospec Pixel Editor is no longer in development and is no longer accepting contributions.**  
+**It remains available at https://lospec.com/pixel-editor in it's current state, but may contain bugs.**
 
-The tool can be viewed online here: https://lospec.com/pixel-editor
+This is a browser based software for creating pixel art
 
 ## Before contributing