Minor changes

- Add `-v` flag to show errors, by default verbose mode is now disabled
- Add `-version` flag to show gau version

Restructure + Bugfixes

Features list:

• Rewrote code base for better readability and genericity
• Add -providers flag to specify which providers to fetch URLs from
• Fix multiple issues
• Split code
• Speed improvements
• Add go module configuration
• Pass unlimited parameters via CLI:

gau --subs example.com example.com ...