docs: add publish command to getting started (#163)

Co-authored-by: Erick Zhao <[email protected]>

README.md

@@ -62,12 +62,20 @@ npm run make
 
 ## Publishing your app
 
-Now you have distributables that you can share with your users. If you run the `publish` script, Electron Forge will then publish the platform-specific distributables for you, using the publishing method of your choice. For more information on what publishers we currently support, check out the [Publishers](config/publishers/) documentation.
+Now you have distributables that you can share with your users. If you run the `publish` script, Electron Forge will then publish the platform-specific distributables for you, using the publishing method of your choice. For example, if you want to publish your assets to GitHub, you can install the GitHub publisher dependency using:
+
+```bash
+npm install --save-dev @electron-forge/publisher-github
+```
+
+Once you have [configured the publisher according to the documentation](config/publishers/github), run the following command to upload your distributables:
 
 ```bash
 npm run publish
 ```
 
+For more information on what publishers we currently support, check out the [Publishers](config/publishers/) documentation.
+
 ## Advanced Usage
 
 Once you've got a basic app starting, building and publishing, it's time to add your custom configuration, which can be done in the `forge.config.js` file. Configuration options are specified in the [Configuration Docs](https://www.electronforge.io/configuration).