Start describing how IPython works
Start describing notebooks for IPython architecture doc
Describe nbconvert in architecture doc
Add diagram of notebook components
Implement a couple of suggestions from @jhamrick
Brief description of IPython.parallel
Mention the term REPL
Refer to octave_kernel, not Oct2Py
Replace stick figure with smiley
Wording tweak
Merge pull request #6719 from takluyver/how-ipy-works-tk

How IPython works document