docs(ngMock): note that inject/module helpers only defined for jasmine / mocha

Closes angular#8694

Author: misutkame

src/ngMock/angular-mocks.js

@@ -2074,6 +2074,7 @@ if(window.jasmine || window.mocha) {
    * @description
    *
    * *NOTE*: This function is also published on window for easy access.<br>
+   * *NOTE*: This function is declared ONLY WHEN running tests with jasmine or mocha
    *
    * This function registers a module configuration code. It collects the configuration information
    * which will be used when the injector is created by {@link angular.mock.inject inject}.
@@ -2116,6 +2117,7 @@ if(window.jasmine || window.mocha) {
    * @description
    *
    * *NOTE*: This function is also published on window for easy access.<br>
+   * *NOTE*: This function is declared ONLY WHEN running tests with jasmine or mocha
    *
    * The inject function wraps a function into an injectable function. The inject() creates new
    * instance of {@link auto.$injector $injector} per test, which is then used for