33Across: Document support for User ID module (#2841)

* Add publisher usage docs for 33Across

* Added 33Across to partners list

* Clarified example pubID

* Reinstated changes that got lost during rebase

* 33across adapter is GDPR compliant

* update docs

* added usp support

* We support Schain!

* Update for video support

* fixes to video params

* fixed context

* fixed instream params

* fix for multi-format

* Fixed Ad Unit titles

* protocols is required

* typo fix

* Added required bidder param

* removed duplicate video params

* formatting edits

* prebid-server adapter will support only single imp reqs

* Updated based in CR

* minor fix

* resolved merge conflicts

* Prebid Server adapter to support multi-imps

* supporting all userIds

Co-authored-by: Gleb Glushtsov <gleb.glushtsov@33across.com>
Co-authored-by: Gleb Glushtsov <glebglushtsov@users.noreply.github.com>
Co-authored-by: Aparna Hegde <ahegde@AHEGDE-MAC.local>
Co-authored-by: Aparna Hegde <ahegde@AHEGDE-MAC.fios-router.home>

dev-docs/bidders/33across.md

@@ -10,6 +10,7 @@ gdpr_supported: true
 getFloor: true
 schain_supported: true
 usp_supported: true
+userIds: all
 gvl_id: 58
 ---