also, update .pre-commit-config.yaml to:
* first change to ./p2, then run the tests (pre-commit deliberately does
not allow this by design [1])
* for the above, the https://github.com/dnephin/pre-commit-golang repo
had to be dropped as it does not allow any customisation either.
also, add some flake updates (would be better split into another commit,
I know):
* use baseurl var
* add statix to shell packages
* fix building p1
refs:
[1]: https://github.com/pre-commit/pre-commit/issues/1110
* create a proper p1.mat project
* create a proper Simulink p1.slx
* add new and correct Simulink simulation output data, previous Simulink data was garbage
* save re-generated pictures with fresh Simulink data in data/m.csv and
reworked python functions (there were errors in the implementation)
* standardise picture naming to one that makes more sense
