add funding file (#2)

Author: cksidharthan

.github/FUNDING.yml

@@ -1,6 +1,6 @@
 # These are supported funding model platforms
 
-github: https://github.com/sponsors/cksidharthan
+github: cksidharthan
 patreon: # Replace with a single Patreon username
 open_collective: # Replace with a single Open Collective username
 ko_fi: # Replace with a single Ko-fi username