Fix home directories with spaces in the path

[nicolaschan]

When the home directory path has a space in the path we get an error like this:

https://github.com/ishaan-jaff/clerkie-cli/archive/refs/tags/v0.0.2-beta.zip
main: line 14: cd: too many arguments
downloading latest release in /home/nicolas/foo bar//.clerkie-cli
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0Warning: Failed to open the file /home/nicolas/foo: Is a directory
100   512    0   512    0     0    578      0 --:--:-- --:--:-- --:--:--  2081
curl: (23) Failure writing output to destination
curl: (6) Could not resolve host: bar
main: line 42: err: command not found
chmod: cannot access 'bar//.clerkie-cli/release.zip': No such file or directory
unzip:  cannot find or open /home/nicolas/foo, /home/nicolas/foo.zip or /home/nicolas/foo.ZIP.
rm: cannot remove '/home/nicolas/foo': Is a directory
rm: cannot remove 'bar//.clerkie-cli/release.zip': No such file or directory
installed clerkie and unzipped
renaming bar/
Clerkie Installed. Open a new Terminal Window to start using

This PR fixes this error by properly quoting all variables. I also fix other shellcheck linting issues and add a GitHub action to automatically check the install script for linting issues.