Document current architecture

[felixhekhorn]

• Define format
• make sure it can be updated later on
• it might make sense to define one document for the Python flow and one for the Rust flow?
• Generated document can be stored in the extras folder

The document should at least mention the following steps:

• build system: poetry vs. maturin
• User entry point
• split in Operator and OperatorMatrixElement ?
• Loop on target interpolation point which can be parallelized
• Loop on source interpolation node and loop over flavors
• scipy.intergate.quad
• quad_ker numba entry point in Python workflow vs. rust_quad_ker entry point in Rust workflow together with the return point to numba
• ekore access in Python workflow vs. ekore access in Rust workflow
• py/ekore bottom vs. rust/ekore bottom
• Linear algebra for solution
• Interpolation polynomial
• versioning: poetry-dynamic-versioning and bump-versions.py