Add TP 2

.gitignore

Pystan/.envrc

Pystan/config/.gitignore

Pystan/config/cfg.py

Pystan/config/constant_propagation.py

Pystan/config/example_constant_propagation.py

Pystan/config/example_interval.py

Pystan/config/example_interval_eval_exp.py

Pystan/config/example_interval_reduce.py

Pystan/config/example_iteration.py

Pystan/config/example_opsem.py

Pystan/config/example_sign.py

Pystan/config/example_sign_eval_exp.py

Pystan/config/example_sign_reduce.py

Pystan/config/example_widen.py

Pystan/config/interval_analysis.py

Pystan/config/iteration.py

Pystan/config/opsem.py

Pystan/config/pyrightconfig.json

Pystan/config/sign_analysis.py