[webpayments] Adding registration proposal (#113)

Adding a new directory for proposals and migrating this registration proposal from the WICG repo to the WG repo. I'm hoping others will either modify this proposal or create new ones that can be discussed.
You can view, comment on, or merge this pull request online at:

  https://github.com/w3c/webpayments/pull/113

-- Commit Summary --

  * Adding registration proposal

-- File Changes --

    A proposals/registration.md (218)

-- Patch Links --

https://github.com/w3c/webpayments/pull/113.patch
https://github.com/w3c/webpayments/pull/113.diff

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Reply to this email directly or view it on GitHub:
https://github.com/w3c/webpayments/pull/113