[Openid-specs-risc] [openid/sharedsignals] 5d6b02: changed SHOULD to MUST for top-level sub_id field

[Atul Tulshibagwale]

  Branch: refs/heads/sub_id-changes
  Home:   https://github.com/openid/sharedsignals
  Commit: 5d6b0261c3f3f1f9b5de5b2d62bf4de886e4ccee
      https://github.com/openid/sharedsignals/commit/5d6b0261c3f3f1f9b5de5b2d62bf4de886e4ccee
  Author: Atul Tulshibagwale <atultulshi at gmail.com>
  Date:   2023-08-09 (Wed, 09 Aug 2023)

  Changed paths:
    M openid-sharedsignals-framework-1_0.md

  Log Message:
  -----------
  changed SHOULD to MUST for top-level sub_id field