This is my first post for a while. I just wanted to let you know that I have been learning how to use git. My github repo is here.
I have placed a number of "books" there which I have worked on in the last year including
MyCrypto (just beginning)
Also, there is a collection of writeups on more than 60 topics in mathematics. The tex files are on github here and the pdfs are on Dropbox here (48 MB).