Additional 'Schedule' type examples

[epaulson]

I'd like to open a pull request to add a few additional examples to the documentation of the schedule type, discussed in #1457, but I wondered if it was easier to do a quick spot-check here first.

For the first additional example, I wanted an example that was similar to the use of the openingHoursSpecification property, but using the Schedule type instead of the OpeningHoursSpecification type, which was a use case considered in 1457. (I'm using the eventSchedule property just as an example but there are lots of things that need a 'schedule' that aren't "events" but also aren't exactly "opening hours" either)

In this example, consider something like a bar, which might be closed entirely on Mondays, open most weekdays and close at exactly midnight on those days, and be open late (past Midnight) on Fridays and Saturdays, and close somewhat early on Sundays. I think that all fits in like so:

    {
      "@context": "https://schema.org",
      "@type": "Event",
      "name": "Schedule for the Week Example",
      "eventSchedule": [
        {
          "@type": "Schedule",
          "startDate": "2016-01-02",
          "repeatFrequency": "P1D",
          "byDay": ["TU,WE,TH"],
          "startTime": "12:00:00",
          "endTime": "00:00:00",
          "scheduleTimezone": "Europe/London"
        },
        {
          "@type": "Schedule",
          "startDate": "2016-01-02",
          "repeatFrequency": "P1D",
          "byDay": ["FR,SA"],
          "startTime": "12:00:00",
          "endTime": "02:00:00",
          "scheduleTimezone": "Europe/London"
        },
        {
          "@type": "Schedule",
          "startDate": "2016-01-02",
          "repeatFrequency": "P1D",
          "byDay": ["SU"],
          "startTime": "12:00:00",
          "endTime": "23:00:00",
          "scheduleTimezone": "Europe/London"
        }
      ]
    }

For another example, I wanted to use an event that occurs on the last day of each month:

    {
      "@context": "https://schema.org",
      "@type": "Event",
      "name": "Last Day Example",
      "eventSchedule":
        {
          "@type": "Schedule",
          "startDate": "2016-12-24",
          "repeatFrequency": "P1M",
          "byMonthDay": [-1],
          "startTime": "09:00:00",
          "endTime": "17:00:00",
          "scheduleTimezone": "Europe/London"
        }
    }