[Openid-specs-risc] [openid/sharedsignals] 748800: fixed README and updated workflow to build CAEP too

[Atul Tulshibagwale]

  Branch: refs/heads/update-readme
  Home:   https://github.com/openid/sharedsignals
  Commit: 748800158da3668e46ee05ff2af62033201dd8fd
      https://github.com/openid/sharedsignals/commit/748800158da3668e46ee05ff2af62033201dd8fd
  Author: Atul Tulshibagwale <atultulshi at gmail.com>
  Date:   2023-07-13 (Thu, 13 Jul 2023)

  Changed paths:
    M .github/workflows/build-everything.yml
    M README.md

  Log Message:
  -----------
  fixed README and updated workflow to build CAEP too