see also previous commit
Also updates `scripting_intro.rst` to use literal includes, and uses individual image outputs to avoid the intermediary `.tex` file to join them all.
Code now resides in `docs/source/code_examples`.
`CHAPTER_Prog` -> `stubnets`
`APPNOTE_011_Design_Investigation` -> `selections` and `show`
`resources/PRESENTATION_Intro` -> `intro`
`resources/PRESENTATION_ExSyn` -> `synth_flow`
`resources/PRESENTATION_ExAdv` -> `techmap`, `macc`, and `selections`
`resources/PRESENTATION_ExOth` -> `scrambler` and `axis`
Note that generated images are not yet configured to build from the new code locations.