Added instructions: contains preface for "userbashrc"

install.sh: now creates the file userbashrc in the modules section
    moves the existing .bashrc to ~/.config/terrorshell/modules/userbashrc so that all pre existing
    aliases will persist
templates/bashrc: added userbashrc to the list of modules
TODO Learn how commit messages work, and proper practice for push's
TODO check existing bashrc for conflicting alias names
I will maybe start working on a module when I get time that will do this.