shape of numpyarray requires more than one time point for reweighting

Due the shape of the numpyarray, reweighting of HDX-MS data with a single time point is not possible.
A simple fix is to add an extra time point at time=0 and deuteration=0 for all peptides.
A specific error message in this regard must be added to the code to avoid confusion.

Start by locating the reweighting input handling and the construction of the NumPy array for peptide time points. Reproduce the single-time-point case and inspect how its shape is handled. Done means the case receives a clear error message or the required zero-time-point data is added consistently for all peptides.

Written by the indexing model from the issue text.