Developing plugins with typescript

I follow the the same instructions for the template described here(, but when i change some sources, changes not affected in the UI. How can i solve this problem?
instaructions that i followed:
-install grafana(v5.2)
-clone the the template into data/plugins directory(i want to develop built-in table plugin, thus table plugin source files copied to the src directory of template)
-yarn install
-grunt watch

but when i login into grafana changes didnt affected in the ui. what is go wrong?is there any other configs that i missed? i also created a custom.ini file with app_mode = development in the conf directory.