Updated readme to contain a more explicit list of objects that have b…

…een exposed

README.md

@@ -15,12 +15,7 @@ Rust bindings for [USD](https://github.com/PixarAnimationStudios/USD).
 - You can create references under prims or as layers.
 - You can traverse the prims in a stage.
 
-# Work to do
-- [ ] Relationships
-- [ ] Schemas
-- [ ] Edit Targets
-- [ ] Variant Sets
-- [ ] Get/Set default root prim
+More more complete list can be found [below](#Progress)
 
 # The parts
 - usd-cpp is a crate to build the cpp shared library and its dependencies (tbb, boost ..).
@@ -87,3 +82,23 @@ for building usd-rs in centos:7 which is the oldest supported linux distribution
 across the vfx industry.
 
 The image is called [luketitley/vfxrs_env_usd](https://hub.docker.com/repository/docker/luketitley/vfxrs_env_usd).
+
+# Progress
+
+This project is currently focused on exposing the top level USD api as much as possible.
+Everything related to UsdStage, UsdPrim and where necessary the lower level types are should be
+exposed, such as VtValue.
+
+The intention is that later on the higher performance sdf and hydra apis are also exposed.
+
+## Usd
+
+|   Object      |     Usable      |
+|---------------|-----------------|
+|  Attribute    |      [x]        |
+|  Prim         |      [x]        |
+|  References   |      [x]        |
+|  Relationship |      [x]        |
+|  Stage        |      [x]        |
+
+