Expose the difficulty adjustment information in an API #622 (#628)

* Added difficulty adjustment information API

* Added Difficulty API in API docs frontend

* Added link to API

* Updated the API implementation of difficulty-adjustment

* Updated API End Point in frontend

* Updated sample API response in frontend

frontend/angular.json

@@ -1,5 +1,8 @@
 {
   "$schema": "./node_modules/@angular/cli/lib/config/schema.json",
+  "cli": {
+    "analytics": "ed0ff723-05da-4a22-b43d-692b797b5243"
+  },
   "version": 1,
   "newProjectRoot": "projects",
   "projects": {