Add .prettierrc.json to configure Prettier, reformat code

__mocks__/@actions/github.ts

@@ -1,34 +1,34 @@
 export const context = {
   payload: {
     pull_request: {
-      number: 123,
-    },
+      number: 123
+    }
   },
   repo: {
-    owner: "monalisa",
-    repo: "helloworld",
-  },
+    owner: 'monalisa',
+    repo: 'helloworld'
+  }
 };
 
 const mockApi = {
   rest: {
     issues: {
       addLabels: jest.fn(),
-      removeLabel: jest.fn(),
+      removeLabel: jest.fn()
     },
     pulls: {
       get: jest.fn().mockResolvedValue({}),
       listFiles: {
         endpoint: {
-          merge: jest.fn().mockReturnValue({}),
-        },
-      },
+          merge: jest.fn().mockReturnValue({})
+        }
+      }
     },
     repos: {
-      getContent: jest.fn(),
-    },
+      getContent: jest.fn()
+    }
   },
-  paginate: jest.fn(),
+  paginate: jest.fn()
 };
 
 export const getOctokit = jest.fn().mockImplementation(() => mockApi);