Add notes on project paths
It is backed by [libuv][http://libuv.org/] to implement IO functionality, and is a work in progress.
+## To build the Wren CLI
+
+### Windows
+
+The `projects/vs20xx` folders contain Visual Studio projects.
+
+### macOS
+
+The `projects/xcode` folder contains an Xcode project.
+
+### Linux
+
+The `projects/gmake` folder contains a `make` project.
+From that folder, run make.
+
+`cd projects/gmake`
+`make`
+
+## Alternative build options
+
+The projects are generated by `projects/premake`.
+You can use premake5 (alpha 14 was used) to generate other projects.
+
+---
+
## Wren is a small, fast, class-based concurrent scripting language
Think Smalltalk in a Lua-sized package with a dash of Erlang and wrapped up in
