Feat: Allow Direct Access to Public Content

[ItzNotABug]

This PR adds the ability to serve static contents, the logic is configurable as well.

Example -

1. File structure -

   public -
       .env
       robots.txt
       app-ads.txt

2. Add the directory -

   express.static('public');

This will serve files in the public directory directly when you do - https://function.com/robots.txt.

Excluding some files not meant for public -

You can also exclude some files, like the .env file in the public directory with either name or a regex -

express.static('public', [/^\..*env.*/i, 'config.php']);

[ItzNotABug]

Base branch used was #view-engine-support.