Tidy up python documentation and add examples

docs/python_api/examples/renderdoc_intro.py

@@ -0,0 +1,28 @@
+import renderdoc as rd
+
+# Open a capture file handle
+cap = rd.OpenCaptureFile()
+
+# Open a particular file - see also OpenBuffer to load from memory
+status = cap.OpenFile('test.rdc', '', None)
+
+# Make sure the file opened successfully
+if status != rd.ReplayStatus.Succeeded:
+    raise RuntimeError("Couldn't open file: " + str(status))
+
+# Make sure we can replay
+if not cap.LocalReplaySupport():
+    raise RuntimeError("Capture cannot be replayed")
+
+# Initialise the replay
+status,controller = cap.OpenCapture(None)
+
+if status != rd.ReplayStatus.Succeeded:
+    raise RuntimeError("Couldn't initialise replay: " + str(status))
+
+# Now we can use the controller!
+print("%d top-level drawcalls" % len(controller.GetDrawcalls()))
+
+controller.Shutdown()
+
+cap.Shutdown()