Add documentation about loading config values programmatically

CHANGELOG.md

@@ -1,7 +1,7 @@
 # Changelog
 
 ## v2.29.0
-* **Change default configuration format to .ini**
+* **Default configuration format is now .ini**
   * Existing `config.json` files will continue to work and will not be deprecated
   * This makes the default configuration format for the bot much more approachable than JSON
 * Config values can now also be loaded from environment variables

docs/configuration.md

@@ -7,6 +7,7 @@ Haven't set up the bot yet? Check out [Setting up the bot](setup.md) first!
 - [Required options](#required-options)
 - [Other options](#other-options)
 - [config.ini vs config.json](#configini-vs-configjson)
+- [Other formats](#other-formats)
 - [Environment variables](#environment-variables)
 
 ## Configuration file
@@ -315,6 +316,11 @@ This is the second line of the greeting."
 }
 ```
 
+## Other formats
+Loading config values programmatically is also supported.
+Create a `config.js` in the bot's folder and export the config object with `module.exports`.
+All other configuration files take precedence, so make sure you don't have both.
+
 ## Environment variables
 Config options can be passed via environment variables.