Add updated ICS file

This ICS includes both meetings defined in terms of their respective local timezones so that they're easy to manage/update later.

The US-time-based meeting will take place on the first Thursday of each month at 10:30am San Francisco local time.

The Asia-time-based meeting will take place on the first Wednesday of each month at 2:30pm Brisbane local time.

The `VTIMEZONE` sections were borrowed from Google Calendar invites to ensure that they're correct, so they might very well be able to be condensed and/or updated.  The `VEVENT` sections were hand-crafted, which is the reason for their field-brevity.

Fixes #12
Closes #13