Updated date in the custom firmware FAQ. Corrected some image paths. Identified the usage of `mhg4s.ihg`, `zaqrc.olc` and `help.lis` resources files (thanks to `nummacway` for the hint!).
Added a new tool, the Generic Image Tool - allows you to convert SF2000 images to PNG, and PNG/JPEG images to SF2000 formats with several options.
Also added a large amount of arcade-specific information thanks to some heroic work by `adcockm#8175`, fixed some typos thanks to `Luke#4448`, and tracked down where an "unused" image was actually being used thanks to `kid_sinn#9691`
* Updated most of the Resources file lists to include firmware-related information (added, (un)changed, removed)
* Added new image resources for the latest May 15th firmware
* Updated some images files previews to contain the fake name extensions as well
* Added detail about the removal of per-game button maps from May 15th firmware
* Renamed the sound previews to contain the fake name extensions as well
