Simplify the Git intro by minimizing new concepts directly not relevent for git about git-intro

[Jyrsa]

I'd suggest print statements in Python. probably simpler than a shell script.

[bast]

I agree that Python is possibly better (more familiar) than shell script. However we can simplify the Python code. I would remove all the __name__ stuff. If you have never coded Python, then this is just confusing. I also like examples with text files but I personally find examples with "radovan added this line" boring. I would go for a recipe or a poem or a song text.

[bast]

We need to replace/simplify this example:

# i am a comment
from hello import say_hello
if __name__ == "__main__":
    say_hello()