Add "castle" filter for fort-awesome icon

[Groman123]

Would be nice to find the fa-fort-awesome icon by searching for a castle....

[tagliala]

Hi!

Thanks for being part of the Font Awesome Community.

This PR is ok for me, since there are other brands with filters (eg: robot filter for android).

I just have a doubt. Quoting from the docs:

• Brand icons should only be used to represent the company or product to which they refer.
• Please do not use brand logos for any purpose except to represent that particular brand or service.

I'm asking a review for this PR, so I can properly manage these in the future

[robmadole]

First off, thanks for spending the time to post this PR. It's sat in the Font Awesome GitHub repo for far too long and we should have responded or addressed the work that you put into this.

Over the past year we've been hard at work on Font Awesome 5. It's now released and this PR no longer applies. So we're going to close it (with an apology for being so tardy).

If you think the work from this still applies feel free to reply and we'll take a second look.

– FA team