Coding Standards in the module

Hi Enzo.

I was checking the module and decided to make a few quick edits in the code to make it follow the coding standards of Drupal.

Basically I did:

• Re-indent some parts of the code, now all the code is indented using two spaces instead of 4.
• I edited the docblocks now they look like the comments in the core of Drupal.
• I added some dots in the end of the comments
• I refactored a little the hook_help() hook, the PHPCS was complaining about the break after the return statement.
• I deleted the hook_theme() because it is not used.
• The opening braces must be in the same line as the functions signature.

And that's it.

I didn't tested the functionality yet, I hope have the chance soon.

In the meanwhile seems the hook_help() needs work because accord with the documentation the function specs the router_name instead of the path.

I will check that and open a new issue with the fix.

Regards.