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!

[kaisalmon]

@JannisX11 Do you know if this image link is correctly configured to work within Blockbench?

[JannisX11]

No, Blockbench doesn't handle images that are part of plugins. You will need to link to a full web address where the image is hosted, you can look at the mesh_tools plugin for example as a reference.

[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