Update README

README.md

@@ -1,7 +1,7 @@
 # JoltC
-C wrapper for [Jolt Physics](https://github.com/jrouwe/JoltPhysics) 5.1.0.
+C wrapper for [Jolt Physics](https://github.com/jrouwe/JoltPhysics) 5.x.
 
-Currently a work in progress. Bindings contain functions that we've needed as part of our game or the Rust bindings we're working on in [jolt-rust](https://github.com/SecondHalfGames/jolt-rust).
+Currently a work in progress. Bindings contain functions that we've needed as part of [our game](https://store.steampowered.com/app/2660180/MEANWHILE_IN_SECTOR_80/) or the Rust bindings we're working on in [jolt-rust](https://github.com/SecondHalfGames/jolt-rust).
 
 The [`JoltC`](./JoltC) directory contains headers for the C interface that you can bind to.
 
@@ -9,6 +9,8 @@ The [`JoltCImpl`](./JoltCImpl) directory contains the C++ implementation of the
 
 ## Goals
 1. Sound C wrapper around current version of Jolt Physics
+	- We avoid relying on unspecified C++ type layout, which means reflecting those types as opaque handles.
+	- We always assert identical layout when creating FFI-compatible versions of C++ types in cases where it makes sense.
 2. Headers suitable for usage in automatic binding generation tools (i.e. Rust `bindgen`, LuaJIT FFI)
 
 ## Building
@@ -29,13 +31,20 @@ cmake --build build
 ## Hello, world!
 A port of Jolt's "HelloWorld" example is provided in [HelloWorld/main.cpp](HelloWorld/main.cpp).
 
+## Jolt's `RefTarget` Types
+Jolt has internal reference counting for a few types along with [good documentation about handling them in C++](https://jrouwe.github.io/JoltPhysicsDocs/5.3.0/index.html#memory-management). This interface to Jolt does not have a generic `Ref`/`RefConst` wrapper, so it's important to be conscious of ref counts when handling these types.
+
+Just like Jolt, this library will return those objects with a reference count of 0. Jolt APIs that accept these types will take ownership of the given value and increment the reference count.
+
+You can use `JPC_{type}_AddRef` and `JPC_{type}_Release`, where `{type}` is the type that directly inherits from `RefTarget<{type}>`, to add or release references. For example, for `FixedConstraint`, use `JPC_Constraint_AddRef` to add a new reference.
+
 ## Other C Wrappers
 Other C wrappers for Jolt Physics include:
 - "JoltC", part of the [zphysics] Zig library started by [Michal Ziulek][michal-ziulek]
 - "JoltC", part of the [jolt-rs] Rust library started by [cohaereo] and a fork of the zphysics C wrapper
 - "joltc", part of the [JoltPhysicsSharp] C# library started by [Amer Koleci][amerkoleci]
 
-The goal of this project is to be the first C wrapper around Jolt Physics that is not part of a larger binding project and to eliminate sources of undefined behavior. It's intended to be useful for any other language-specific bindings and to reduce the need to duplicate work.
+The goal of this project is to be a C wrapper around Jolt Physics that is not part of a larger binding project and to eliminate major sources of undefined behavior. It's intended to be useful for any other language-specific bindings, but naturally these bindings were born out of the goal of creating Rust bindings to Jolt Physics.
 
 ## License
 Licensed under either of