feat(parser): Only use icons which are wanted for inclusion if given …

[lubber-de]

Description

This PR adds a proposal solution to support CSS generation for only wanted icons to be able to reduce the overall CSS.
If somebody wants to only generate CSS for some known icons instead of the whole Font Awesome set, the file include_icons.json, should be adjusted to hold an array of font-awesome names.

[
  "address-book",
  "address-card",
  "adobe"
]

[y0hami]

I like the idea and the code is good but I don't think this should be in src and we should move it into the CLI itself like asking the user if they want to only include some icons and if they do they specify a file path to a JSON file like the proposal which the CLI will then use.

[y0hami]

We should also add a not include alternative.

[lubber-de]

Agreed, as said, it was just a proposal. You may adjust the code accordingly when you've time and use this PR only as reference and close it. 😉