Please excuse the last commit lacking a changelog.

+ PDK installation uses Volare, transparently to the user: all they have to do is type "make", where it will get OpenLane and the PDK
+ CI now uses Volare to either **get** or **build** the PDK (if not found), which speeds up the fastest test set by around 60%.
+ Added rudimentary dependency installation instructions.
+ pyyaml folded into the repo, so users without pip can still run issue surveys
~ Open PDKs updated: Parasitics are now extracted using a rules file based on [spef-extractor](https://github.com/Cloud-V/spef-extractor) as a ***temporary*** measure
~ Issue survey no longer checks for click and pyyaml: a venv is used in those scenarios.
~ OpenLane build no longer uses the host filesystem as an intermediary, instead using a templated dockerfile with an N-stage build for N tools, saving IO operations (40% improvement measured)
~ Old PDK targets renamed to build-pdk-conda, includes SRAM by default
~ Replaced python3 ./env.py issue-survey with `make survey`
- Removed Fault from documentation (until I get the chance to work on it)