I want to create a Resource Pack where Stone Blocks can have grass grow on them like how grass grows on dirt blocks to create grass blocks. How do I achieve this?
That would have to be a mod. It would change the block state. You can't do that with a resourcepack.
"We live on a placid island of ignorance in the midst of black seas of infinity, and it was not meant that we should voyage far."
I want it to be like how Bdouble00's cobblestone is randomized. I know that the way he does it is by altering the block state files, so is there a way to alter the files for stone in order to achieve grassy stone without modding?
I don't think so, although doing that would be pretty easy to do in a mod.