A Custom Element for an analog clock.

• mode (string): stopwatch or clock.
• size (number): Width and height in pixel.
• marks (number): Number of markings on the edge of the clock for telling the time.
• ticks (boolean): Whether to display the hour numbers on the dial.

• ::part(tick): The numbers on the dial.
• ::part(tick): The numbers on the dial.
• ::part(tick1)...::part(tick12): Each of the nubmers on the dial.
• ::part(clock): The clock face.
• ::part(marks): The markings on the edge of the clock.
• ::part(hand-hour): The hour hand.
• ::part(hand-minute): The minute hand.
• ::part(hand-second): The second hand.

• analogClock.mode = 'clock'/'stopwatch' switches mode between clock and stopwatch.
• analogClock.toggleStopwatch() starts and stops the stop watch.
• analogClock.resetStopwatch() resets stopwatch to 0.
• analogClock.getTimeElapsed() get time elapsed in ms.

In Safari, quickly switching between mode might result in janky animation. Related bug reports:

• https://bugs.webkit.org/show_bug.cgi?id=191265
• https://bugs.webkit.org/show_bug.cgi?id=201736
• https://bugs.webkit.org/show_bug.cgi?id=229437