added npm link to build script

build_tracim_frontend.sh

 cd frontend_lib
 log "npm i"
 npm i
+log "npm link"
+npm link
 log "npm run buildtracimlib"
 npm run buildtracimlib
 cd -
 cd frontend_app_html-document
 log "npm i"
 npm i
+log "npm link tracim_frontend_lib"
+npm link tracim_frontend_lib
 log "npm run build # for frontend_app_html-document"
 npm run build
 log "cp dist/html-document.app.js"
 cd frontend
 log "npm i"
 npm i
+log "npm link tracim_frontend_lib"
+npm link tracim_frontend_lib
 log "npm run servdev-dashboard # for frontend"
 npm run servdev-dashboard