hugo: update fit links

hugo/content/py/fitting/advanced/find-background/index.md

hugo/content/py/fitting/advanced/fit-along-slices/index.md

hugo/content/py/fitting/advanced/fit-with-masks/index.md

hugo/content/py/fitting/advanced/multiple-datasets/index.md

hugo/content/py/fitting/basic/consecutive-fitting/index.md

hugo/content/py/fitting/basic/minimizer-settings/index.md

...nt/py/fitting/extended/custom-objective-function/index.md

...content/py/fitting/extended/experiment-at-galaxi/index.md

...itting/extended/external-minimizer-with-plotting/index.md

hugo/content/py/fitting/extended/external-minimizer/index.md

...ntent/py/fitting/extended/fit-with-uncertainties/index.md

.../py/fitting/extended/polarized-spinasymmetry-fit/index.md

...tent/py/fitting/extended/real-life-reflectometry/index.md

...tent/py/fitting/extended/reflectometry-honeycomb/index.md

...ntent/py/fitting/extended/reflectometry-pt-layer/index.md