RobertJaro/NF2: NF2 v0.4.1

v0.4.1 Release Notes Added bundled YAML config templates under nf2/configs. nf2-extrapolate and nf2-extrapolate-series now support installed config names such as nf2/cartesian/sharp_cea.yaml. Removed duplicate examples/configs; nf2/configs is now the single source of truth. Made optional error-file placeholders flexible: omitted *_err arguments are skipped cleanly. Updated docs for SHARP CEA and HMI spherical single/series runs, including optional error-file arguments. Bumped package, docs, and conda recipe version to 0.4.1.