Initial import of Template:Storage:synchronous_io_warning
Initial import of Template:Storage:synchronous_io_warning

https://developer.mozilla.org/en-US/docs/Template:Storage:synchronous_io_warning

Contributors (by MDN username):
* sdwilsh
* trevorh

jpmedley/kumascript,jpmedley/kumascript,a2sheppy/kumascript,a2sheppy/kumascript