TODO: document ffrunner setup instructions

[clicktodev]

we should generate a document on how to setup a full development environment for every platform because right now, the readme is missing instructions on how to setup the ffrunner folder which is required to run and build the project.

should be as simple as converting the rust workflow into a md document

[CakeLancelot]

Documentation on this aspect would be good, definitely. Perhaps even better - we could add an npm script to automatically download pre-compiled ffrunner/dxvk/webplayer binaries, in case the developer doesn't want to setup the MinGW toolchain (or it is not readily available for their platform).
Related: #11

[clicktodev]

will do asap