docs: interface changes

changelog.md

@@ -4,6 +4,10 @@
 ## 2.1.0
 - **Internal Changes:**
   - Removed `compareVersions()` and `compareVersionArrays()` in favor of including the [`compare-versions`](https://npmjs.com/package/compare-versions) library
+- **Plugin Changes:**
+  - Renamed interface events to be more consistent
+  - Added new component `createLongBtn()` to create a button with an icon and text (works either as normal or as a toggle button)  
+    The design matches that of the subscribe button on YTM's channel pages, but the consistent class names make it easy to style it differently.
 
 <!-- <div class="pr-link-cont">
   <a href="https://github.com/Sv443/BetterYTM/pull/TODO" rel="noopener noreferrer">See pull request for more info</a>

contributing.md

@@ -156,6 +156,9 @@ If you want your plugin to be displayed in the readme and possibly inside the us
   
 **Helpful knowledge:**
 - TypeScript (for type safety and better autocomplete)
+- The source code of BetterYTM  
+  This is especially regarding the files `src/interface.ts`, `src/types.ts`, `src/siteEvents.ts` and `src/observers.ts`
+- Being on the lookout for pull requests, since they will list new features and changes to the interface
 - This document, as it contains most of the information you need to know about the BetterYTM interface, or at least points you to the places where you can find it
   
 <br>