Add a few more release notes

Author: lord

CHANGELOG.md

@@ -14,9 +14,12 @@
   - New default colors!
   - New spacings and sizes!
   - System-default typefaces, just like GitHub
+- Added search input delay on large corpuses to reduce lag
 - We even bumped the major version cause hey, why not?
 - Various small bug fixes
 
+Thanks to everyone who helped debug or wrote code for this version! It was a serious community effort, and I couldn't have done it alone.
+
 ## Version 1.5.0
 
 *February 23, 2017*