RNN docs

[jeremiedb]

This PR is to augment the documentation around the recurrence structure to address frequent questions raised about how to handle the recurrent tools for various use cases.

This is presented as an additional component to the current Recurrent doc. I'm unclear if it would be preferable to attempt to blend the current docs into a single page on recurrence?

[ToucheSir]

This is great! I vote for merging with the current RNN page, as having a "continued" page would be somewhat awkward for navigation.

[jeremiedb]

@ToucheSir Makes much sense! So I'll rework to merge some the more detailed Recurrent cell logic from the original docs into the new expanded explanations.

[jeremiedb]

@CarloLucibello / @DhairyaLGandhi Update to the recurrent docs would be now ready for review.

[jeremiedb]

@ToucheSir Just bumping to avoid it falls in a crack. Is there anything else needed for merge?

[CarloLucibello]

best documentation page we'll have in Flux, thanks!

bors r+

[bors]

Build succeeded:

• ci/gitlab/gitlab.com