Add support to file.allxyz

As the title suggests, I would like to ask if it is possible to add support for .allxyz files, such as those generated by ORCA during NEB calculations or scans.

An example is provided below:


Attached is an image from gMolden showing the energy profile of the sequence of structures.

Yeah, no problem: Add support for "allxyz" from Orca - trajectory files by ghutchis · Pull Request #1995 · OpenChemistry/avogadrolibs · GitHub

All it really does is add the allxyz as a possible extension. (You can also just rename the extension yourself.)