Added Mr Salmon's Baked Ambient Occlusion

[kaisalmon]

This PR adds a plugin which allows baked world-space ambient occlusion, to create an instant first-pass at shading.

If there are any changes needed to have this merged, please let me know!

[JannisX11]

Hey, I took a look today, here are some notes:

• Please check README.md, there are a bunch of important submission guidelines and requirements. For example a min version of 4.8.0 or higher to be able to use the new repo structure.
• Sideload the plugin into Blockbench from this directory to test how it loads. There are still some issues, like the icon doesn't load because it's missing the file extension in the plugin file.
• Generally please make sure the plugin metadata in plugins.json and in the actual plugin file are identical and check that formatting is not messed up.

No major notes on the functionality of the plugin itself. It's integrated pretty nicely and works well. Only suggestion I have is to not limit the width of the dialog, to make it easier to adjust options. You could even set it to be resizable on the X axis.

[kaisalmon]

Thanks @JannisX11. I had thought I had followed those instructions, but I will check again and make sure I've fixed the issues I missed! I will fix the width issues, and some of the issues related to rotations which were highlighted on the discord in the coming days

[kaisalmon]

Hi @JannisX11! Thanks for your patience! I got the sideloading working (I couldn't find the documentation on that, so I had to change plugin_loader.js directly? If this is the intended way, I think it might be worth documenting that (or making it easier to set up a custom CDN in the dev tools). I could look into making a PR to help with that, if you'd like (Or, if I just missed the documentation, I'm sorry!!)

I've now updated all the meta-data and triple checked that it works, and it now installs nicely in-editor, and the images all come through nicely!