Improve FBX exporter to better support game engines

Here's a prime example of a developer who has managed to fix some of the issues of FBX exporter for Blender. It is being maintained, but this frankly needs to be done baseline to vastly improve compatibility with game engines such as Unity and Unreal.

github.com/A-Ribeiro/CustomBlenderFBXExporter

My biggest issue with current FBX in Blender is that the Armature becomes a ghost bone at the top of the hierarchy when importing into game engines. That makes it also impossible to set up your own "Root" bone inside the Armature to have specific controllers for it when using drivers. In game engines it also causes headaches where you want to animate from the root bone, so any additional bloat bones should never appear.

Here's how the skeleton looks like in Blender:

This is how it looks like in Unreal if the Armature is being named something else, such as "Skeleton":

This is how it looks like when using the modified FBX exporter from GITHUB:

Please add this option in for future versions of Blender!