docs: add faq (#23)

Author: zeke

readme.md

@@ -13,7 +13,7 @@ Before using this module, make sure your Electron app meets these criteria:
 - Your app runs on macOS or Windows
 - Your app has a public GitHub repository
 - Your builds are published to GitHub Releases
-- Your builds are code-signed
+- Your builds are [code signed]
 
 ## Installation
 
@@ -58,6 +58,25 @@ Options:
 - `updateInterval` String (optional) - How frequently to check for updates. Defaults to `10 minutes`. Minimum allowed interval is `5 minutes`.
 - `logger` Object (optional) - A custom logger object that defines a `log` function. Defaults to `console`. See [electron-log](https://github.com/megahertz/electron-log), a module that aggregates logs from main and renderer processes into a single file.
 
+## FAQ
+
+#### What kinds of assets do I need to build?
+
+For macOS, you'll need to build a `.zip` file and include it in your GitHub Release. 
+Use [electron-forge] or [electron-installer-zip] to package your app as a zip.
+
+For Windows, you'll need to build a `.exe` file and include it in your GitHub Release. 
+
+#### Why is my app launching multiple times?
+
+Windows apps have an update process that requires multiple application restarts.
+You can use the [electron-squirrel-startup](https://github.com/mongodb-js/electron-squirrel-startup) module to improve this 
+behavior.
+
+#### Can I use this module by uploading my private app's builds to a public GitHub repository?
+
+Yes :)
+
 ## License
 
 MIT
@@ -66,4 +85,8 @@ MIT
 
 If your app is packaged with `electron-builder`, you may not need this module. 
 Builder has its own built-in mechanism for updating apps. Find out more at 
-[electron.build/auto-update](https://www.electron.build/auto-update).
+[electron.build/auto-update](https://www.electron.build/auto-update).
+
+[electron-forge]: https://github.com/electron-userland/electron-forge
+[electron-installer-zip]: https://github.com/mongodb-js/electron-installer-zip
+[code signed]: https://github.com/electron/electron/blob/master/docs/tutorial/code-signing.md