The contents of the left-hand navigation pane is found in file leftnav.html in the base directory. Its content is installed in other pages by the software that builds the index.html pages.
Editing leftnav.html and rebuilding the index.html pages will install the new navigation pane.
Run bin/buildTerm term to rebuild the files for term (term). The (term) should have a form similar to 2020-Fall or 2020-Spring. The name is case-sensitive.
Run bin/buildAcademicYear year to rebuild the files that are part of an adademic year directory. The (year) has a form similar to 2021-2022.
Run bin/build to build all files, for all academic years and terms.