feat: add contribution type promotion (#339)

Author: tenshiAMD

src/util/contribution-types.js

@@ -1,7 +1,7 @@
 const _ = require('lodash/fp')
 const repo = require('../repo')
 
-const defaultTypes = function(repoType) {
+const defaultTypes = function (repoType) {
   return {
     a11y: {
       symbol: '️️️️♿️',
@@ -136,9 +136,13 @@ const defaultTypes = function(repoType) {
       symbol: '📹',
       description: 'Videos',
     },
+    promotion: {
+      symbol: '📣',
+      description: 'Promotion',
+    },
   }
 }
 
-module.exports = function(options) {
+module.exports = function (options) {
   return _.assign(defaultTypes(options.repoType), options.types)
 }