add documentation for downloading document issue (#4904)
add documentation for downloading document issue (#4904)

* fix download document bugs

* add documentation

* Update src/foam/nanos/http/AuthWebAgent.java

Co-authored-by: Joel Hughes <6b2ec7a157637e7456307a107b45ae958a538724@users.noreply.github.com>
foam-framework/foam2,jacksonic/vjlofvhjfgm,foam-framework/foam2,foam-framework/foam2,jacksonic/vjlofvhjfgm,foam-framework/foam2,jacksonic/vjlofvhjfgm,foam-framework/foam2