fix: as I dev I need access to base url that I can find locale files in the broswer

for example /js/en.US.json
fix: html lang attribute should only be 2 chars and the default lang should be "en-US" not "en"
fix: change the default lang to "en-US" from "en"
feat: as a dev I want a way to load translation file dynalicly
feat: as a dev I want to include unicode CLDR data into translation file to support number, date formating