Describe newly coded features in readme

README.md

@@ -3,3 +3,26 @@
 _Under heavy development!_
 
 Let's use Blender to create BIM models, because why not?
+
+## Features
+
+ - IFC4 is a first-class citizen. IFC4 has been an ISO standard since 2013, with
+   the latest published in 2018. In contrast, other programs are dragging their
+   feet with IFC2X3, published back in 2005.
+ - Use Blender to do digital modeling! Blender is an amazing open-source
+   software that supports the full 3D content creation pipeline that the CG
+   industry uses. Don't let your designs fall short just because your modeling
+   tool isn't good enough!
+ - Create complex spatial structures with multiple sites, buildings, facilities,
+   bridges, and building parts. In contrast, some BIM tools (uh, Revit?) don't
+   even allow you to specify buildings.
+ - Classify any geometry as any IFC type. Just because it is a wall doesn't
+   mean you should be limited to modeling it in a certain way. Easily change
+   from one type to another without damaging your geometry.
+ - Allow BIM objects to instance a shared geometric representations. This allows
+   you to place the same shape in multiple objects without drastically
+   increasing your filesize.
+ - Provide a custom value to any simple IFC attribute of an IFC product.
+ - Create product types that regular IFC products can inherit attributes from.
+ - Define your own property sets with control over exactly how the data in the
+   property sets are stored.