Ender 3 Pro Rear electronics case for extender 400 (draft)

This is a Remix from https://www.thingiverse.com/thing:4269399.

I have an Ender Extender 400 (coming) and really like the idea of this.

Whats Changed:

- Moved the Outer edge out making the base and Lid 235mm in length
- Add in two sets of feet for additional buck converters

Things to Note:

I haven't yet had the chance to print it as I don't have a bed big enough, hence the draft version at this stage, once I have had the chance to print I will then look to feedback here any updated files.