v0.1.0

Added

• The first release of sermod, the server for end-to-end
  encrypted conversations between people over MLS (RFC 9420). It serves
  the API of api/openapi.yaml under /v1/messaging: the directory of
  each person's devices with their vouches and revocations, the key
  packages a device offers, conversations and their ordered log of MLS
  messages with one commit per epoch, each group's latest group info,
  Welcomes, the recovery record, and whether a person is one of a
  conversation's people.
• Every commit is checked before it is kept: its signature against the
  sender's leaf, the leaf against a device of the person whose token
  sent it, and what it changes against the conversation's rules.
• A person is the sub of a token from any OpenID Connect issuer in
  SERMO_OIDC_ISSUERS, and every request is decided by the endpoint at
  SERMO_AUTHORIZER_URL, which must refuse the probe before the server
  starts. Without one, the server decides by its member policy.
• State is kept in Postgres with SERMO_DATABASE_URL, migrated at start
  over that direct endpoint, and served over SERMO_DATABASE_POOL_URL
  when it names a pooled one. Without a database it is kept in memory.
• A container image, sermod, for linux/amd64 and linux/arm64, which
  reports its release with sermod -version and at /version.