Ports: Fix ports linting, ffmpeg is missing from AvailablePorts.md

Author: https://github.com/bgianfo
Commit: https://github.com/SerenityOS/serenity/commit/1d3bc482a5c
Pull-request: https://github.com/SerenityOS/serenity/pull/6730

Ports/AvailablePorts.md

@@ -27,6 +27,7 @@ Please make sure to keep this list up to date when adding and updating ports. :^
 | [`figlet`](figlet/)                    | FIGlet                                                     | 2.2.5                    | http://www.figlet.org/                                                         |
 | [`flatbuffers`](flatbuffers/)          | Flatbuffers                                                | 1.12.0                   | https://github.com/google/flatbuffers                                          |
 | [`flex`](flex/)                        | flex                                                       | 2.6.4                    | https://github.com/westes/flex                                                 |
+| [`ffmpeg`](ffmpeg/)                    | ffmpeg                                                     | 4.4                      | https://ffmpeg.org                                                             |
 | [`freetype`](freetype/)                | FreeType                                                   | 2.10.4                   | https://www.freetype.org/                                                      |
 | [`frotz`](frotz/)                      | Frotz                                                      | 2.53                     | https://gitlab.com/DavidGriffith/frotz                                         |
 | [`gcc`](gcc/)                          | GNU Compiler Collection                                    | 10.3.0                   | https://gcc.gnu.org/                                                           |