PSF reference: can now read insertion codes

MDAnalysis/mdanalysis#2053 was closed by
PR MDAnalysis/mdanalysis#4582 on 2024-05-30
and PSF files with insertion codes can now be read.

Author: orbeckst

doc/source/formats/reference/psf.rst

@@ -24,9 +24,7 @@ As a NAMD file is space-separated, files with missing columns can cause MDAnalys
 
 .. _`This can cause issues for PSF files written from VMD.`: https://github.com/MDAnalysis/mdanalysis/issues/2061
 
-PSF files can encode insertion codes. However, MDAnalysis `does not currently support reading PSF files with insertion codes`_. 
-
-.. _`does not currently support reading PSF files with insertion codes`: https://github.com/MDAnalysis/mdanalysis/issues/2053
+PSF files can encode insertion codes and MDAnalysis will read them.
 
 
 
@@ -68,4 +66,4 @@ no CHEQ::
 
 **NAMD**
 
-This format is space separated (see the `release notes for VMD 1.9.1, psfplugin <http://www.ks.uiuc.edu/Research/vmd/current/devel.html>`_). 
+This format is space separated (see the `release notes for VMD 1.9.1, psfplugin <http://www.ks.uiuc.edu/Research/vmd/current/devel.html>`_).