docs(options): added urls for new inject options (#1959)

Author: knagaitsev

lib/options.json

@@ -404,8 +404,8 @@
       "http2": "should be {Boolean} (https://webpack.js.org/configuration/dev-server/#devserverhttp2)",
       "https": "should be {Object|Boolean} (https://webpack.js.org/configuration/dev-server/#devserverhttps)",
       "index": "should be {String} (https://webpack.js.org/configuration/dev-server/#devserverindex)",
-      "injectClient": "should be {Boolean|Function}",
-      "injectHot": "should be {Boolean|Function}",
+      "injectClient": "should be {Boolean|Function} (https://webpack.js.org/configuration/dev-server/#devserverinjectclient)",
+      "injectHot": "should be {Boolean|Function} (https://webpack.js.org/configuration/dev-server/#devserverinjecthot)",
       "inline": "should be {Boolean} (https://webpack.js.org/configuration/dev-server/#devserverinline)",
       "key": "should be {String|Buffer}",
       "lazy": "should be {Boolean} (https://webpack.js.org/configuration/dev-server/#devserverlazy-)",