meeting: Bump January meeting from the 3rd to the 10th

Catching up with:

On Thu, Dec 07, 2017 at 09:14:32AM -0600, Chris Aniszczyk wrote [1]:
> btw, I bumped the January meeting a week later due to the holidays,
> that should solve issues and updated the calendar invite

I've used RDATE [2] to add the new date and EXDATE [3] to remove the
old date.  The ICS was validated with [4].

Also add some wiggle room to the README text, although I don't know
that it's worth adding text for each exception there.  After the
meeting, we can leave the exception information in the iCalendar entry
without bothering anyone, but we'd need more churn to remove it from
the README.

[1]: https://groups.google.com/a/opencontainers.org/d/msg/dev/FzclHQsMH_c/QKJMybRkBAAJ
     Subject: Re: 2017-12-06 agenda
     Date: Thu, 7 Dec 2017 09:14:32 -0600
     Message-ID: <CAJg1wMQFVvT+UiJ1gj3m2AzLQEus82eoWRVVtBEe+ZBMxskq=w@mail.gmail.com>
[2]: https://tools.ietf.org/html/rfc5545#section-3.8.5.2
[3]: https://tools.ietf.org/html/rfc5545#section-3.8.5.1
[4]: https://icalendar.org/validator.html

Signed-off-by: W. Trevor King <[email protected]>

README.md

@@ -54,7 +54,7 @@ When in doubt, start on the [mailing-list](#mailing-list).
 
 ### Meetings
 
-The contributors and maintainers of all OCI projects have monthly meetings at 2:00 PM (USA Pacific) on the first Wednesday of every month.
+The contributors and maintainers of all OCI projects have monthly meetings, which are usually at 2:00 PM (USA Pacific) on the first Wednesday of every month.
 There is an [iCalendar][rfc5545] format for the meetings [here](meeting.ics).
 Everyone is welcome to participate via [UberConference web][uberconference] or audio-only: +1 415 968 0849 (no PIN needed).
 An initial agenda will be posted to the [mailing list](#mailing-list) in the week before each meeting, and everyone is welcome to propose additional topics or suggest other agenda alterations there.

meeting.ics

@@ -21,9 +21,11 @@ END:DAYLIGHT
 END:VTIMEZONE
 BEGIN:VEVENT
 UID:[email protected]
-DTSTAMP:20170821T200000Z
+DTSTAMP:20171207T173000Z
 DTSTART;TZID=America/Los_Angeles:20170906T140000
 RRULE:FREQ=MONTHLY;INTERVAL=1;BYDAY=1WE
+RDATE;TZID=America/Los_Angeles:20180110T140000
+EXDATE;TZIP=America/Los_Angeles:20180103T140000
 DURATION:PT1H
 SUMMARY:OCI TDC Meeting
 DESCRIPTION;ALTREP="https://github.com/opencontainers/runtime-spec#