https://docs.github.com/en/site-policy/other-site-policies/github-and-trade-controls

MIT does not force you to not make your project free.

Given the double negative and the ambiguity of “free,” I don’t know what you’re trying to say here.

CTRL+M is like pressing ENTER. Kernigan & Pike, 1984: UNIX Programming Enviornment

RETURN is an example of a control character — an invisible character that controls some aspect of input and output on the terminal. On any reasonable terminal, RETURN has a key of its own, but most control characters do not. Instead, they must be typed by holding down the CONTROL key, sometimes called CTL or CNTL or CTRL, then pressing another key, usually a letter. For example, RETURN may be typed by pressing the RETURN key or, equivalently, holding down the CONTROL key and typing an ‘m’. RETURN might therefore be called a control-m, which we will write as ctl-m.

Best practice is not to use raw credentials on the command line because it exposes them in process listings and shell history files.

https://git-scm.com/docs/gitcredentials