Use staging analytics key in documentation
Use staging analytics key in documentation

Use the publicly available staging key in the readme.  Without this key,
the app may fail to run locally when developing.

Signed-off-by: Ryan Y <8b814a5aa9a201d2e1bf7a02c3b0d197e9e28c79@protingumas.com>

Code4HR/okcandidate,stanzheng/okcandidate