Moved the last files out of the resources directory.
Some tidy up/reformatting of the extensions to allow literalincludes from `my_cmd.cc`.
Most (all?) of the getting started guidelines file is either in the quick guide section, or sections referenced by it. Instead of including it verbatim, we'll instead just leave a reference to it but then jump straight into the quick guide.
Include an image for the absval generated module. Still needs more surrounding text but it's good enough for now.
Also includes some other minor tidying, including removing the no longer used abc_01 code example.
Makefiles now have `clean` target.
Also fixed top level makefile calls to images directory.
More yosys scripts instead of inline yosys commands in makefiles (which also means they can be included in the accompanying document when talking about the image generated).
Fixed another couple image generators that were still outputting pdf directly.
Fixed some hanging image references which hadn't been updated.
Adjusted some text related to images, and included a couple more intermediate images on `memdemo`.
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.