more changes to readme

Author: drebbe-intrepid

README.md

@@ -19,16 +19,22 @@ Python wrapper for interfacing to IntrepidCS Hardware.
 ### Linux
 
 - Linux builds use [libicsneo](https://github.com/intrepidcs/libicsneo) and are built against [manylinux](https://github.com/pypa/manylinux) using cibuildwheel.
+- libicsneolegacy.so is bundled with the wheel and python_ics will automatically use it.
 
 ### MacOS
 
 - Mac builds use [libicsneo](https://github.com/intrepidcs/libicsneo) and are built using cibuildwheel
+- libicsneolegacy.dylib is bundled with the wheel and python_ics will automatically use it.
 
 # Documentation
 
 http://python-ics.readthedocs.io/
 
 
+# Building from source
+
+- Building from source requires clang and clang-format to be present on the build machine.
+
 # License - MIT
 
 Copyright (c) Intrepid Control Systems, Inc.