Add some Windows specifics to readme

Author: kriskbx

readme.md

@@ -40,14 +40,14 @@ Install the gtt command line interface using yarn:
 yarn global add gitlab-time-tracker --prefix /usr/local
 ```
 
-... or using npm:
+... or using npm (recommended on **Windows** operating systems):
 
 ```shell
 npm install -g gitlab-time-tracker
 ```
 
 Run the config command to create a config file and open it in your default editor.
-If nothing happens, open the file manually: `~/.gtt/config.yml`
+If nothing happens, open the file manually: `~/.gtt/config.yml` - on Windows: `C:\Users\YourUserName\.gtt\config.yml`
 
 ```shell
 gtt config
@@ -145,6 +145,8 @@ If a local configuration file is present it will extend of the global one and ov
 If you don't want to extend the global configuration file, set the `extend` option in your local config to `false`.
 So you can use gtt easily on a per project basis. Make sure to add .gtt.yml to your gitignore file if using a local configuration.
 
+If nothing happens, open the file manually: `~/.gtt/config.yml` - on Windows: `C:\Users\YourUserName\.gtt\config.yml`
+
 ### II) time tracking
 
 Time tracking enables you to monitor the time you spent on an issue or merge request locally.