Add events to a EventSeries rather than individually

[jmarmstrong1207]

Hi! This is James, one of the IT Specialists at CAIS and assistant for Daniel.

This PR makes it so all singular events will be added into an EventSeries, rather than added as their completely separate events. This would deprecate the Update and Delete script as the user can update/delete from the google calendar webpage

I have tested it and it does work for me, but obviously test it on your end to see if it works for you as well

[saegl5]

Hi James, thank you for your contributions. I will be looking into them shortly.

[saegl5]

Tested it, and it works marvelously! 👍 I plan to merge, adapt your code, then retest.

• [x] merged
• [x] adapted (see 5567c2292d69c15fc64ddbbf4e46ade19091ca1e)
• [x] retested

[saegl5]

TO DO

• [x] bringing some changes from main branch to development branch
• [x] retest dev branch
• [x] double-check if recurrences would deprecate the update and delete script (they should, agreed!)
  • [x] update script: add script doesn't deprecate it due to start and end dates
    can work around that by editing individual and subsequent events on different dates <--- BROKEN fixed in a9991d016f40b345154f663c1149f62fdfc74bea
  • [x] delete script: add script doesn't deprecate it due to start and end dates, either can work around that, too, the same way <--- BROKEN fixed in a9991d016f40b345154f663c1149f62fdfc74bea
• [x] merge development into main

[saegl5]

@jmarmstrong1207

Okay, should be all set.

Additional features:

• Adapted the recurrence technique for creating a calendar. At least now, users wouldn't need to remove the calendar entirely to delete all events. Reverted, since such events cannot recur (titles cycle)
• Used variables for colors in the Index.html, in case you would like to more easily customize its look. Example: adding red colors.

Thank you, again, for your contribution. If you have any other ideas, let me know. 感谢你～～ (Daniel too)