Add timestampts to facts

[lalalune]

One of the features of bgent is that there is a facts evaluator, which derives facts from the conversation. Recent facts are recalled, along with "relevant" facts -- i.e. facts that in some way relate to the current conversation.

Facts should have timestamp, timestamp should be turned into X minutes ago, X hours ago, X days ago

We should create a set of functions (or find a library) that turns time information into semantic info. For example, "3 days ago".

For display facts, we should try to not polute with too much "3 days ago", but sort the facts by date and have one header for each day, or "last month", or whatever looks clean and makes sense.

• Add functions to convert timestamp to "x minutes/days/weeks/months ago" (probably a library on npm for this)
• Add this to the formatting of facts that are returned
• Test this with facts to verify that relevant facts from long ago are indeed brought up