Libssh dash docset generator generates docset for libssh library. If you want to have docset with correct libssh logo in docset. Copy img/logo.png to output/html/org.libssh.docset/icon.png and add it to Dash.app.
On Mac OS X you can build docset with these simple commands. On other systems docsetutils should be installed.
doxygen Doxyfile
cd output/html
make
cp -r org.libssh.docset ~/Desktop/