No Box2D To PlayRho Migration Guide

[louis-langholtz]

Expected/Desired Behavior or Experience:

There's a guide written in markdown for helping people transition from Box2D code to PlayRho. Among other things, it should mention:

• The transition from using shape types to using the visitor design pattern for this.
• The transition from using joint types to using the visitor design pattern for this.
• Circle shapes have been renamed disk shapes.
• Settings have become runtime parameters via StepConf.
• The base float32 type has morphed into the playrho::Real type supporting any fundamental floating point type as well as user definable types that at least satisfy the LiteralType concept, have supporting common mathematical functions, and have a specialization of the std::numeric_lists template class for them.
• Gravity, acceleration and forces all rolling into bodies' acceleration property.

Actual Behavior:

There's currently no transition guide like this.

[louis-langholtz]

Hmm... just remembered: there's PlayRho/Changes.md that relates to this. Because there's this document already which I think just needs review and some updates, I'm re-targeting this issue to the Beta launch.

[louis-langholtz]

I'd love to have a document for this that was focused on explaining PlayRho in terms of Box2D but I don't want to hold up a release 1.0 for this.