Fix outstanding sphinx warnings;
- Change mycells.lib to use `text` parsing instead of (currently) unsupported `Liberty`.
- Remove unused `troubleshooting.rst`, moving the todo into the index.
- Use `:file:` role for file names, as well as `:makevar:` and `:program:`.
- Remove deprecated `linux-arm` and `linux-riscv64` oss-cad-suite targets.
- Add link to ABC.
- More (and better) links to code examples. Formatted `:file:` text with link
to source on github.
- Includes a few extra todos (mostly picking up inline code blocks and a couple
intro reminders).
- Fixing a few missing `:yoscrypt:` and `:cmd:ref:` tags.
- Reflowing some paragraphs for spacing/width.
- Filling out index descriptions for `using_yosys` and `using_yosys/synthesis`.
- To discourage skipping over these index pages, the toctree in
`using_yosys/index` is hidden and instead has inline links to the two
subsections.
- Tidying todos.
- Moves technology mapping to `techmap_synth`, leaving the techmap by example in
the internals section. `yosys_flows` gets split up, with the coarse-grain
intro replaced by `synthesis/index`, the extract pass moving to
`synthesis/extract` and model checking to `more_scripting/model_checking`.
Updates code examples, removing `counter_outputs.ys` in favour of a single script. Also adds a .gitignore for the output file `synth.v`.
`example_synth.rst` still pending updated example.
Krystine Sherwin
Rui Chen