Automate updating to new semesters

[edfan]

This one is more involved, but it would be really really nice to have.

Here's a rough list of steps:

• Copy the current set of files into a new folder under semesters/
  • e.g., for Fall '20, copy index.html to semesters/f20/fall.html and script-compiled.js to that directory
  • in fall.html, fix top-level script / image references by adding ../../
• Add the new semester to all of the dropdowns, which involves changing every single previous semester
  • This should really be refactored, but I'm not super sure how. Maybe the object tag works, maybe it should just be a jQuery hack.
• Update new_scripts/coursews.py to pull the new semester, then run the normal update process
• Fix comma placement in index.html (this is annoying to explain but intuitive, just look at the diff in that file for a semester update)
• Update the MIT schedule for GCal export in script.js
  • This is also really annoying- it would be great to scrape the calendar, or have a script to generate the recurrence rules.
  • Try not to forget how RDATE works! Say there are Monday classes on a Tuesday- put the Tuesday date in the Monday slot in RDATE and add the Tuesday in the Tuesday slot to EXDATE.
• Update LocalStorage variable names in script.js (find/replace fall20 -> spring21)
• and remember to recompile using new_scripts/compile.sh!

[cjquines]

also, might need to change "Not offered 20xx-20yy" in index.html

note that RDATE is "additional dates they'll happen" and EXDATE is "date that it won't happen"