Add GitHub Sponsors button

.github/FUNDING.yml

@@ -0,0 +1,14 @@
+# These are supported funding model platforms
+
+github: [srajan-kiyotaka]# 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
+# ko_fi: # Replace with a single Ko-fi username
+# tidelift: # Replace with a single Tidelift platform-name/package-name e.g., npm/babel
+# community_bridge: # Replace with a single Community Bridge project-name e.g., cloud-foundry
+# liberapay: # Replace with a single Liberapay username
+# issuehunt: # Replace with a single IssueHunt username
+# lfx_crowdfunding: # Replace with a single LFX Crowdfunding project-name e.g., cloud-foundry
+# polar: # Replace with a single Polar username
+# buy_me_a_coffee: # Replace with a single Buy Me a Coffee username
+# custom: # Replace with up to 4 custom sponsorship URLs e.g., ['link1', 'link2']