Auto rotate banner text according to Election Day calendar

[karpet]

Currently we switch the home page banner intro text manually after each Election Day calendar milestone (day after registration closes, day after Advance Ballot deadline, day after Election Day, etc).

Let's automate that rotation with some pre-defined rules.

If we have special keys in the translations.json file for each milestone change, then the app can do the calendar math and automatically pick the banner text based on what day it is.

This ticket represents figuring out:

• milestone days
• what calendar math to apply
• what special translation key to use for each milestone

[karpet]

Thought: I wonder if a calendar.json file would make sense. The structure might be an array (list) of election season objects, where the keys are milestone days and the values are dates. Essentially turning https://sos.ks.gov/elections/important-election-dates.html into a structured list. Where no time is listed, the implicit time is 23:59:59 (end of day).

[
  {
    "name": "2024 Presidential Preference Primary",
    "election": "2024-03-19",
    "reg_deadline": "2024-02-20",
    "adv_start": "2024-02-28 00:00:00",
    "adv_end": "2024-03-18 12:00:00",
  }
]