gmx select, append new generated group to input ndx

[adamhospital]

gmx_select has an optional input named input_ndx_path. The functionality of this bb is exactly the one of the GROMACS select tool: it produces a new index file (ndx) with (only) the newly generated group. It would be really good if the output ndx file could contain not only the new group, but all the groups defined in the input ndx file + the new group (append).

[PauAndrio]

Testing

[github-actions]

This issue is stale because it has been open for 30 days with no activity. If there is no more activity in the following 14 days it will be automatically closed.

[github-actions]

This issue was closed because it has been inactive for 14 days since being marked as stale.

[PauAndrio]

Please, @adamhospital could you check if all the features of this issue have been correctly implemented?

[github-actions]

This issue is stale because it has been open for 30 days with no activity. If there is no more activity in the following 14 days it will be automatically closed.

[github-actions]

This issue is stale because it has been open for 30 days with no activity. If there is no more activity in the following 14 days it will be automatically closed.

[github-actions]

This issue is stale because it has been open for 30 days with no activity. If there is no more activity in the following 14 days it will be automatically closed.