docs: forgot to add fOptimizer tool to readme list

Author: craftablescience

README.md

@@ -446,6 +446,7 @@ These are only the tools and games using `sourcepp` that I know of. If you would
 ### Tools
 
 - [fgptool](https://github.com/craftablescience/fgptool): A tool to crack the filepath hashes in The Orange Box PS3 file groups.
+- [fOptimizer](https://github.com/fxington/foptimizer): A GUI-based collection of tools written in Python for cutting down on unnecessarily bloated Garry's Mod addon sizes.
 - [gimp-vtf](https://github.com/chev2/gimp-vtf): A GIMP plugin to load and save VTF files.
 - [gm_addon_optimization_tricks](https://github.com/wrefgtzweve/gm_addon_optimization_tricks): A desktop tool to optimize Garry's Mod addons/maps.
 - [GodotSource](https://github.com/craftablescience/godotsource): A work-in-progress set of bindings to connect the `sourcepp` libraries to Godot. Allows GDScript to work with the libraries, and allows Godot to directly load Source engine assets from a user project or from installed Source games.