[General Change]: Sectioned Sidebar

### Problem

There are new utils coming every minute, with 34 new util suggestion issues open right now. Which will soon make it quite difficult to find what you are looking for in the sidebar. This issue tries to address that problem.

### My proposal
Instead of having all the utils in random places, we split them up into sections/categories.
Here are the 3 categories that I suggest: Administration, Development and Miscellaneous. Utils such as the Start File Generator would go in Development, whilst things like Server Jars, which are more related to setting a server up, would go in Administration. All other things such as Skin Stealer, Cape Stealer and Firework Creator would be a good fit for Miscellaneous.

### Extra Info

Another thing that could be changed would be the text font if the character restriction becomes apparent because of this change. I suggest trying out the font size that Kotlin uses for their docs, 13px, as the have this segmentation in their sidebar too.

Start by locating the current sidebar and the utility navigation entries. Review how the existing utilities are organized, group them into Administration, Development, and Miscellaneous as proposed, and check that every utility remains discoverable and that the sidebar still fits its available space.

Written by the indexing model from the issue text.