fix: install script on windows

[hdeadman]

What

Fix install.sh script for windows (mingw/msys2 bash).

Why

The install script wasn't working on windows b/c the released binary for windows has a .exe extension on it which made the script error with a 404. Also, the USE_SUDO variable should be set to false by default on windows (otherwise piping script to bash won't work).

Implications

An alternative fix would be to change the releases to not include the .exe extension on the windows binary but maybe that was done for use outside of mingw where the install.sh script wouldn't be used. The install script still saves k3d to /usr/local/bin/k3d without the .exe extension and it works without the .exe extension (in msys2/mingw). It would work the same way if it was saved as k3d.exe.

[hdeadman]

When I initially tested this PR locally with MSYS2, it worked, but then I added a github action workflow to run install.sh on ubuntu, mac and windows and it failed on windows. Github's windows image uses the bash that comes with Git for Windows and that is different in some ways from MSYS2. It doesn't include /usr/local/bin, but they do set ~ to the user's windows home directory (/c/Users/xyz) and they put ~/bin first in the path so it's sort of the equivalent of /usr/local/bin. The ~/bin folder doesn't exist by default, despite being in the path, so this change creates it if it doesn't exist and puts k3d in it (only if /usr/local/bin not available and only on windows).

[iwilltry42]

LGTM

[iwilltry42]

I'm personally not testing too much on Windows, so this is a nice fix, thank you very much @hdeadman! 👍