MSC3856: Threads List API (#3856)
* Initial MSC3856 draft.
* s/filter/include/g
* Fix typo.
Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
* Add link to the current spec.
Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
* Link to MSC3440 for related_by_rel_types.
* Rework and clarify intro.
* Clarify what is returned by the API.
* Add a note on dir.
* Add info on ignored users.
* Clarifications from review.
Co-authored-by: Travis Ralston <travisr@matrix.org>
* Add notes about MSC2836.
* Add a comma to enum values.
Co-authored-by: Erik Johnston <erik@matrix.org>
* Simplify pagination.
* Fix typos.
Co-authored-by: Alexey Rusakov <Kitsune-Ral@users.sf.net>
Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
Co-authored-by: Travis Ralston <travisr@matrix.org>
Co-authored-by: Erik Johnston <erik@matrix.org>
Co-authored-by: Alexey Rusakov <Kitsune-Ral@users.sf.net>
