Add complex pycode example, generating tasks and then parsing tags to select source files. Warn against doing it, and reiterate the usefulness of `--dumptasks` and `--dumpcfg`.
Modify gen.sh for modifiable script/task and to echo how it was called (in case they need to be regenerated, which isn't a problem for the regular example/task1 but is for the complex one).
Move parser generation into a seperate file to avoid import issues with bad python modules during docs gen.
With the requirements.txt provided to readthedocs, there shouldn't need to be any other changes?
Also I've never been able to run `make test` so I'm not actually sure if the changes break sby, but they shouldn't.