Update Gemspec

Author: joeldrapper

green_dots.gemspec renamed to quickdraw.gemspec

@@ -17,6 +17,7 @@ Gem::Specification.new do |spec|
 	spec.metadata["homepage_uri"] = spec.homepage
 	spec.metadata["source_code_uri"] = "https://github.com/joeldrapper/quickdraw"
 	spec.metadata["changelog_uri"] = "https://github.com/joeldrapper/quickdraw"
+	spec.metadata["funding_uri"] = "https://github.com/sponsors/joeldrapper"
 
 	# Specify which files should be added to the gem when it is released.
 	# The `git ls-files -z` loads the files in the RubyGem that have been added into git.