Docs: Add logo config example (#135)

* Docs: Add logo config example

Verbatim copy of a Slack answer given by @danwom 

Having a few specific examples to go from in config docs always give you a good start

* Adjust based on review suggestions

Thanks for the quick AND thorough/thoughtful response!

* More specific guidance

On another read-through. You're right!

docs/configuration.md

@@ -10,6 +10,12 @@ For more information on how the configuration is being loaded and used, please r
 ### Application Config
 Certain features of the React application import variables from an [AppConfig](https://github.com/lyft/amundsenfrontendlibrary/blob/master/amundsen_application/static/js/config/config.ts#L5) object. The configuration can be customized by modifying [config-custom.ts](https://github.com/lyft/amundsenfrontendlibrary/blob/master/amundsen_application/static/js/config/config-custom.ts).
 
+#### Example: Add a custom logo
+
+1. Add your logo to the folder in `amundsen_application/static/images/`
+2. Set the the `logoPath` key on the `AppConfigCustom` object in [config-custom.ts](https://github.com/lyft/amundsenfrontendlibrary/blob/master/amundsen_application/static/js/config/config-custom.ts). For example Lyft uses the value `"/static/images/lyft-logo.svg"`
+3. Rebuild/redeploy. The `npm run build` step will rebuild scripts file to reference the new logo image, and the `python3 setup.py install` step will updated deployed files and make the new image available on the server.
+
 ### Custom Fonts & Styles
 Fonts and css variables can be customized by modifying [fonts-custom.scss](https://github.com/lyft/amundsenfrontendlibrary/blob/master/amundsen_application/static/css/_fonts-custom.scss) and
 [variables-custom.scss](https://github.com/lyft/amundsenfrontendlibrary/blob/master/amundsen_application/static/css/_variables-custom.scss).