Add RenderPather tutorial, tutorial README, and some minor doc updates

examples/tutorial/README.md

@@ -1 +1,39 @@
-TODO write tutorial readme
+masque Tutorial
+===============
+
+Contents
+--------
+
+- [basic_shapes](basic_shapes.py):
+    * Draw basic geometry
+    * Export to GDS
+- [devices](devices.py)
+    * Reference other patterns
+    * Add ports to a pattern
+    * Snap ports together to build a circuit
+    * Check for dangling references
+- [library](library.py)
+    * Create a `LazyLibrary`, which loads / generates patterns only when they are first used
+    * Explore alternate ways of specifying a pattern for `.plug()` and `.place()`
+    * Design a pattern which is meant to plug into an existing pattern (via `.interface()`)
+- [pather](pather.py)
+    * Use `Pather` to route individual wires and wire bundles
+    * Use `BasicTool` to generate paths
+    * Use `BasicTool` to automatically transition between path types
+- [renderpather](rendpather.py)
+    * Use `RenderPather` and `PathTool` to build a layout similar to the one in [pather](pather.py),
+        but using `Path` shapes instead of `Polygon`s.
+
+
+Additionaly, [pcgen](pcgen.py) is a utility module for generating photonic crystal lattices.
+
+
+Running
+-------
+
+Run from inside the examples directory:
+```bash
+cd examples/tutorial
+python3 basic_shapes.py
+klayout -e basic_shapes.gds
+```