Bug: Improper handling of date strings on event pages

[liashahnazaryan]

Description: The dates displayed in the Important Dates section on the website's event pages do not consistently match what's specified in the wmt_events.json, events.json, and the event's .md files. When there is only general text in the date box, such as "To be announced (follows EMNLP)," it appears fine. However, when a date is accompanied by additional text, only the date itself is displayed.

Steps to reproduce the behavior:

1. Go to https://machinetranslate.org/wmt24 or https://machinetranslate.org/eamt-2024
2. Scroll down to the Important Dates section
3. Compare the displayed dates with the corresponding dates in the wmt_events.json, events.json, wmt24.md, and eamt-2024.md files

Expected behavior: The dates displayed on the event pages should match what's specified in the corresponding data files, including any additional text accompanying the date.

Screenshots [optional]:

[tovmasharrison]

I have fixed the bug regarding the WMT events date and will push it soon. However, all date entries should be given in machine-readable format (YYYY-MM-DD). Hence, we came to the conclusion not to give date ranges and only specify the start dates.

I think if there isn't a fixed date we can either skip it or give the median, and if it's unknown, then skipping it should be the option.

What do you think @bittlingmayer ?

(cc) @cefoo

[tovmasharrison]

I have fixed the bug related to the WMT event date generation in #608.