MSYS/Mingw was deprecated since v4.0 and it is removed in v5.0. Please
follow the getting started guide of the documentation to set up a
Windows Command Line or Power Shell based environment.
When user forgot to add git.exe or python to the PATH, there was a not
very helpful error message.
This improves the error with which tool is misssing and shows a link to
the espressif installer tool.