Docs: Unnecessary prefix copied from copyable terminal code blocks

[VictorIreri]

There are a few instances, such as on the Contribute page where there are copyable terminal code blocks with the prefix foo@bar $. I understand the prefix is just meant to help the user but it should be excluded when the user selects the copy button.

marathon/docs/docs/intro/contribute.md

Line 20 in 48c3c9f

foo@bar $ git clone https://github.com/MarathonLabs/marathon.git

In some cases, the prefix is omitted. Perhaps this is preferable?

marathon/docs/docs/intro/contribute.md

Line 39 in 48c3c9f

git clone https://github.com/MarathonLabs/marathon.git

[VictorIreri]

I guess this is an enhancement, not a bug, but I can't change the label.