Noissue - Enable test runner to run on Windows and add documentation

README.md

 Adblock Plus for Chrome, Opera, Microsoft Edge and Firefox
 ==========================================================
 
 This repository contains the platform-specific Adblock Plus source code for
 Chrome, Opera, Microsoft Edge and Firefox. It can be used to build
 Adblock Plus for these platforms, generic Adblock Plus code will be extracted
 from other repositories automatically (see _dependencies_ file).
 
 Note that the Firefox extension built from this repository is the new
 [WebExtension](https://developer.mozilla.org/en-US/Add-ons/WebExtensions).
 The source code of the legacy Adblock Plus extension
 can be found [here](https://hg.adblockplus.org/adblockplus).
 
 Building
 ---------
 
 ### Requirements
 
 - [Mercurial](https://www.mercurial-scm.org/) or [Git](https://git-scm.com/) (whichever you used to clone this repository)
 - [Python 2.7](https://www.python.org)
   - [The Jinja2 module](http://jinja.pocoo.org/docs) (>= 2.8)
   - For signed builds: [PyCrypto module](https://www.dlitz.net/software/pycrypto/)
 - [Node.js](https://nodejs.org/) (>= 7)
 
+### Building on Windows
+
+On Windows, you need a [Linux environment running on WSL](https://docs.microsoft.com/windows/wsl/install-win10).
+Then install the above requirements and run the commands below from within Bash.
+
 ### Building the extension
 
 Run one of the following commands in the project directory, depending on your
 target platform:
 
     ./build.py build -t chrome -k adblockpluschrome.pem
     ./build.py build -t edge
     ./build.py build -t gecko
 
 This will create a build with a name in the form
@@ skipping 34 matching lines @@
 
 The build script calls the ensure_dependencies script automatically to manage
 the dependencies (see _dependencies_ file). Dependencies with local
 modifications won't be updated. Otherwise during development specifying a
 feature-branch's name for a dependency's revision is sometimes useful.
 Alternatively dependency management can be disabled completely by setting the
 _SKIP_DEPENDENCY_UPDATES_ environment variable, for example:
 
     SKIP_DEPENDENCY_UPDATES=true ./build.py devenv -t chrome
 
-Running the unit tests
-----------------------
+Running tests
+-------------
+
+### Unit tests
 
 To verify your changes you can use the unit test suite located in the _qunit_
 directory of the repository. In order to run the unit tests go to the
 extension's Options page, open the JavaScript Console and type in:
 
     location.href = "qunit/index.html";
 
 The unit tests will run automatically once the page loads.
-You can also run these tests with a headless Firefox or Chromium process.
-Install the dependencies first:
+
+### External test runner
+
+There is also an external test runner that can be invoked from the
+command line in order to run the unit tests along some integration
+tests on different browsers, and automatically runs the linter as well.
+
+On Windows, in order to use the test runner, in addition to setting up a Linux
+environment as outlined above, you need to have Node.js installed in your native
+Windows environment. Then run the commands below from within PowerShell or
+cmd.exe (unlike when building the extension which needs to be done from Bash).
+
+Make sure the required packages are installed and up-to-date:
 
     npm install
 
 Start the testing process for all browsers:
 
     npm test
 
 Start the testing process in one browser only:
 
     npm test -- -g <gecko/chrome>
 
 Linting
 -------
 
 You can lint the code using [ESLint](http://eslint.org).
 
 You will need to setup first. This will install our configuration
 [eslint-config-eyeo](https://hg.adblockplus.org/codingtools/file/tip/eslint-config-eyeo)
 and everything needed after you run:
 
     npm install
 
 Then you can run to lint the code:
 
     npm run lint