### What does this merge request add?

This MR:

* Reformats almost everything
* Corrects grammar, makes things clearer
* Removes deprecations (that I'm aware of)
* Makes things linkable and findable via links and the sidebar
* Mentions the change metadata.desktop -> metadata.json
* Explains some SVG changing things

### Related Issues

This MR requires !285 

### Screenshot of the result (optional)

Notice the sidebar, which now shows clickable and easy to find components for reference:

![image](/uploads/b31d4c96ece04f757e5bc32652deaccb/image.png)
![image](/uploads/ae59f9de0f6d2794ede4739cddd015ef/image.png)

### How to test this MR

```bash
git clone https://invent.kde.org/documentation/develop-kde-org.git
cd develop-kde-org
git mr 288
hugo server
```