Adding prettier

Update package.json

Author: aminya

package-lock.json

@@ -43,6 +43,7 @@
     "@types/object-hash": "^1.3.1",
     "@types/semver": "^7.1.0",
     "@types/underscore": "^1.9.4",
+    "prettier": "latest",
     "tslint": "latest"
   },
   "scripts": {
@@ -105,5 +106,10 @@
   "package-deps": [
     "ink",
     "language-julia"
-  ]
+  ],
+  "prettier": {
+    "semi": false,
+    "tabWidth": 2,
+    "printWidth": 120
+  }
 }