Add newly identified specs

[dontcallmedom]

2 new TC39 stage 3 proposals (error cause & temporal); device-posture is a derivative of already included screenfold; IndexDB3 is set to superseded IndexDb-2
fixes #260

[tidoust]

Device Posture is not a derivative of Screen Fold, it is the new name of the spec, and https://w3c.github.io/screen-fold/ redirects to https://w3c.github.io/device-posture/

So Screen Fold needs to be removed from the list.

I believe that Device Posture is about to be published to /TR, so we can perhaps wait a couple of days until it's done to update the list, so that we can add the right URL directly.

[dontcallmedom]

ha, thanks I had missed that! what change to the PR are you suggesting? leaving screen-fold as is?

[tidoust]

a, thanks I had missed that! what change to the PR are you suggesting? leaving screen-fold as is?

Yes, I would leave screen-fold in the list and ignore device-posture until it gets published to /TR. At worst, we'll get a reminder next week.