Documentation about sly

[joaotavora]

I am closing/merging this issue with #9, where the goal is to rewrite the manual for SLY.

To answer your question: You can do it and mostly everything should feel the same as long as you replace "slime" with "sly" in every reference. But some things will surprise you. So the best thing to do, whenever that happens, is to make a comment in issue #9. Or, better yet, open a pull request for the ./doc/sly.texi file and correct them there immediately.

Thanks for your support. Your example is very spot-on. However, to be fair, there is an argument to be made for changing names, one of coexistence in a shared namespace. Operating systems normally don't have that problem.