Full Rewrite | Fix #183 #179 #178 #176 #174 #155

[BUGFIX] auth-utils: Use loopback method to fetch authorizaton code | Fix #183

flags: -h: Support showing help for multiple specified flags at once

flags: Add more documentation

[FEATURE] Support for sub-folders with --create-dir flag. | Resolve #155

install.sh: Do not fail if username is in small case

[SKIP-CI] Fix some shellcheck warinings

Use grep for -ex and -in flag | Resolve #176

Full rewrite