RFE: Add tooltips to shader properties

[skeletonbow]

Shaderfilter has no tooltips to explain what each shader property is for, nor way of specifying such. The current convention is to put a fake "string" property in the source called "Notes" and put a blurb of terse text instructions there to document some of the shader functionality.

By removing this convention and replacing it by using a combination of tooltips and a button that hyperlinks to opening a manual on the web with detailed instructions for the user, and possibly a YouTube tutorial for how to use the given shader, it would greatly improve the end-user experience of using shaders, while allowing people to use more of the shaders as they'd be able to figure out how they work more easily. It would also reduce the number of people potentially seeking technical support in web forums or github issues, as well as filing bug reports unnecessarily.