Add Gallium docs.

In Sphinx/ReST format.
diff --git a/src/gallium/docs/source/cso.rst b/src/gallium/docs/source/cso.rst
new file mode 100644
index 0000000..f00cc51
--- /dev/null
+++ b/src/gallium/docs/source/cso.rst
@@ -0,0 +1,7 @@
+CSO
+===
+
+.. toctree::
+   :glob:
+
+   cso/*