adding parts to the users guide regarding the Default guesser and guess_topologyAttributes

[aya9aladdin]

adding part to the universe page regarding the new guess_topologyAttributes
link: https://aya9aladdin.github.io/UserGuide/universe.html#guessing-topology-attributes

adding a new page for describing the guesser module and moving the guessers to a separate section called guessers list
link: https://aya9aladdin.github.io/UserGuide/formats/guessing.html

[orbeckst]

There is a conflict that needs to be resolved. I looked at it but I am not sure if the new text on guessers is supposed to be added to the other conflicting text or if it's supposed to (partially?) replace it. This requires an expert.

[orbeckst]

@aya9aladdin can you find the time to resolve the conflicts in this PR? That would then allow us to have a look.

It would be really good to have in-depth notes on the new guessers in the User Guide!

[orbeckst]

I think I figured out how the conflict needed to be resolved (old guesser text went into DefaultGuesser) but please double check.

[lilyminium]

Thanks for starting this @aya9aladdin and for tidying it up @orbeckst! As the guesser API has evolved quite a bit since this text was last updated, IMO it'll be easier to close this PR and start afresh. I've opened #409, if you have time @aya9aladdin it'd be great to get your thoughts on the notes there.