feat: add new milestone trigger in GitHub

packages/backend/src/apps/github/info.json

@@ -404,6 +404,45 @@
           "name": "Test trigger"
         }
       ]
+    },
+    {
+      "name": "New milestone",
+      "key": "newMilestone",
+      "interval": "15m",
+      "description": "Triggers when a new milestone is created",
+      "substeps": [
+        {
+          "key": "chooseAccount",
+          "name": "Choose account"
+        },
+        {
+          "key": "chooseTrigger",
+          "name": "Set up a trigger",
+          "arguments": [
+            {
+              "label": "Repo",
+              "key": "repo",
+              "type": "dropdown",
+              "required": true,
+              "variables": false,
+              "source": {
+                "type": "query",
+                "name": "getData",
+                "arguments": [
+                  {
+                    "name": "key",
+                    "value": "listRepos"
+                  }
+                ]
+              }
+            }
+          ]
+        },
+        {
+          "key": "testStep",
+          "name": "Test trigger"
+        }
+      ]
     }
   ]
 }