Add some instructions to the README for packaging archives locally (#27116)
Add some instructions to the README for packaging archives locally (#27116)


cbracken/flutter,cbracken/flutter,flutter/flutter,cbracken/flutter,cbracken/flutter,cbracken/flutter,flutter/flutter,flutter/flutter,tvolkert/flutter,flutter/flutter,cbracken/flutter,cbracken/flutter,Hixie/flutter,flutter/flutter,Hixie/flutter,tvolkert/flutter,Hixie/flutter,tvolkert/flutter,flutter/flutter,Hixie/flutter,cbracken/flutter,tvolkert/flutter,Hixie/flutter,flutter/flutter,Hixie/flutter,flutter/flutter,tvolkert/flutter,Hixie/flutter,Hixie/flutter,Hixie/flutter,flutter/flutter,tvolkert/flutter,Hixie/flutter,tvolkert/flutter,cbracken/flutter,tvolkert/flutter,cbracken/flutter,flutter/flutter,tvolkert/flutter,tvolkert/flutter