RegEx pattern to extract multiplelines title in TXT file

What would be the pattern for a regular expression to extract the titles (Titre) from the attached txt file?
You will see that titles can be on one, two, three or more lines. I would like to get all of them.
I've got the same issue with the Editeur section.
Thanks

Salut!
Here's a proposal :

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Thanks GC for this solution but I thought there would be a fancy pattern to do this by its own.
I hope I would have other answers though.

For the befenit of all, here is what I found to work in this situation:
Pattern="Titre[\S\s]*?)Éditeur"
It will select all characters and as many lines as there are between the words "Titre:" and "Éditeur:"