Fix c3dfileadapters docs (#2676)
Fix c3dfileadapters docs (#2676)

* Fix doxygen comment that includes Python and Matlab code snippets 

* Add snippet for retrieval of individual tables from C3DFileAdapter

* Update C3DFileAdapter.h

Use variable not class name to invoke read, and use single quotes

* Update C3DFileAdapter.h

Update Matlab code snippet per PR review.

* Update C3DFileAdapter.h

Change quotes in Matalb snippet

opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core