Add GitHub Sponsors username to FUNDING.yml

Updated GitHub funding model to include username.

.github/FUNDING.yml

@@ -1,6 +1,6 @@
 # These are supported funding model platforms
 
-github:
+github: [Shnimlz]
 # Replace with up to 4 GitHub Sponsors-enabled usernames e.g., [user1, user2]
 patreon: # Replace with a single Patreon username
 open_collective: # Replace with a single Open Collective username