improve development doc
improve development doc

mkeilman/sirepo,radiasoft/sirepo,mrakitin/sirepo,mrakitin/sirepo,mrakitin/sirepo,radiasoft/sirepo,mrakitin/sirepo,radiasoft/sirepo,mkeilman/sirepo,radiasoft/sirepo,mkeilman/sirepo,mkeilman/sirepo,radiasoft/sirepo