synthesis fixes

[rolypolytoy]

Hi @openpowerwtf,

Since the PR wasn't properly merged into main I've remade those changes. The previous synthesis file was a skeleton so I've added functionality to it, and put netlists (sky130 and gate-level) in the pd/synth repo. I've also added all the relevant logs that Yosys generated, added a copy of the sky130.lib file in the repo if people want to generate netlists within it, and in general populated the pd/synth repo with an entirely functional implementation, with both netlists and netlist-generation capabilities provided.

Changelog:

• Changed synth.yo to synth.ys, since that's the proper extension (old change, merge issues?)
• Uncommented the synthesis-breaking line from tri.vh (old change, merge issues?)
• Added netlist-generation logic to synth.ys since previously it didn't generate any.
• Added a new synth_sky130.ys file to allow for SKY130 synthesis. In this vein, added a valid .lib file for the SKY130 PDK in the same repo.
• Removed the previously generated yosys logs, since they were from the old, skeleton netlist, and added up-to-date Yosys logs from the synth.ys file change made. You can re-add these if it's important, but those logs are just what the CLI auto-generates.
• Added both the generated netlists (netlist.v is the gate-level netlist, sky130.v is the SKY130 netlist) to the synthesis folder, to just allow people to directly use it if they don't want to synthesize it themselves.

Let me know if there are any changes that need to be made.