docs(usage): add basic information on how to use the plugins

Author: NickDJM

README.md

@@ -7,3 +7,12 @@ This package aims to add a few useful tools to help speed up development of them
 **Can't you do this yourself by editing some variables?**
 
 Of course you can! This package exists purely to make it faster to replicate some commonly used customizations.
+
+## Usage
+
+There are a couple ways in use these plugins:
+
+1. Add all of them to your project by importing the `plugin.scss` file found in the root `scss/` directory, or
+2. Add individual plugins by importing the other `.scss` files found in the root `scss/` directory.
+
+Once you have done that, you can use them as you would any other bootstrap feature.