Add additional suggested metadata fields (#6)

* Add color and icon

* Fix syntax, add author

Author: ava-cassiopeia

action.yml

@@ -1,5 +1,9 @@
 name: 'Publish to NPM and GitHub'
 description: 'Publishes an NPM package to NPM and GitHub.'
+author: 'Ava Mattie'
+branding:
+  icon: 'box'
+  color: 'gray-dark'
 inputs:
   npm-package-name:
     description: 'The name of the package to publish on NPM.'