fixed annoyance in AA mol2 reader

[bc118]

I fixing an annoyance in the mol2 reader for atomistic. If the 2nd column in the mol2 is C1 to CN, and CN is large, you had to manually change them, just like adding CH3 for UA (Example: changing C1 to C or H5 to H). I am now reading only the C in C1 or H in H3 from this column, which will allow users to not have to manually manipulate the mol2 file to contain only characters; now mosdef-gomc will omit the integers from the 2nd column.

[codecov]

Codecov Report

Attention: 3 lines in your changes are missing coverage. Please review.

Comparison is base (5eb8f38) 90.83% compared to head (9a59c9f) 90.84%.

Files	Patch %	Lines
mosdef_gomc/formats/gmso_charmm_writer.py	88.00%	3 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #81   +/-   ##
=======================================
  Coverage   90.83%   90.84%           
=======================================
  Files          10       10           
  Lines        6786     6802   +16     
=======================================
+ Hits         6164     6179   +15     
- Misses        622      623    +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.