Update time-line with recent (April 2024) changes to lore dates

[Wedge009]

Describe the desired feature

As highlighted in #8839, the wiki has not been updated to correspond with recent revisions to the lore, particularly in the area of dates.

https://wiki.wesnoth.org/Timeline_of_Wesnoth

[Wedge009]

I could try to do this myself but I don't know what changes have been made or what is 'canonical' even for 1.18, let alone @nemaara's grand designs for 1.20 onwards.

[Wedge009]

Possibly impacted by any changes from resolving #8238, #8363, #8387, #8558.

[Wedge009]

@Dalas121 Not sure if this is something you should note as part of your new position.

[Dalas121]

Thanks for the ping. Many campaign authors (including me!) use the wiki's timeline as a source, so we definitely want it to be accurate. I'll make a note to revise is once TSG and/or TDG goes mainline.

I'm not an expert on other time periods, but will support any changes to fix timeline/lore issues related to them.

[Wedge009]

I don't think anyone can be expected to know every nuance of the lore, but anything treated as a source should ideally be kept up-to-date. My mistake in #8839 was what prompted this request.