Add contributors plugin (#126)

source/plugins/contributors/metadata.yml

@@ -0,0 +1,23 @@
+name: "🏅 Contributors"
+cost: N/A
+supports:
+  - repository
+inputs:
+
+  # Enable or disable plugin
+  plugin_contributors:
+    description: Display repository contributors
+    type: boolean
+    default: no
+
+  # Base reference (commit, tag, branch, etc.)
+  plugin_contributors_base:
+    description: Base reference
+    type: string
+    default: ""
+
+  # Head reference (commit, tag, branch, etc.)
+  plugin_contributors_head:
+    description: Head reference
+    type: string
+    default: master