This is a template for making a plugin in WordPress. For those who don’t want to read the long documentation on making a plugin this will get you started.
The icon.png file is the icon that will show in the left menu bar.
The css file will be included in all pages for custom CSS code. You can make your own classes and IDs here to custom style things in your templates.
If you have ever found an example online of how to do something in WordPress and that example says to modify your functions.php file, DON’T DO IT! A WordPress update could wipe out that custom code! Using this PHP file you can paste that code in it and keep your custom code throughout any updates. It also makes it easier to find the code. The commented top of the PHP file is where you can change things like the plugin name, the author, website and version.
But otherwise this is a great way to get started making a plugin for WordPress!