Update lyx-2.4 docs

[Daniel]

On 2023-01-29 17:37, Jürgen Spitzmüller wrote:
> Am Sonntag, dem 29.01.2023 um 17:23 +0100 schrieb Jean-Pierre Chrétien:
>> I would like to search easily what has been updated since (but for
>> the new index
>> features that I have  already updated in the UserGuide).
>> Is it possible to search for modifications after a given date in the
>> documents ?
>> I could search for changes in Trac, but is is quite lengthy.
> 
> Document > Track Changes > Accept and Reject Changes. This dialog has
> the change dates (not ideal for sure).

I am curious, since I don't have an entry named "Accept and Reject 
Changes". Did you mean "Merge Changes..."?

Daniel