changelog: get unreleased entries from commit trailers

Asking contributors to update the CHANGELOG.md file is causing lots of
merge conflicts. Introduce a new workflow where contributors can attach
changelog entries in patches via git trailers.

Changelog-added: For new features.
Changelog-fixed: For bug fixes.
Changelog-changed: For behaviour or config format changes.
Changelog-deprecated: For deprecation or removal of functionality.

If a complete trailer is longer than 72 characters, it can be continued
by indenting extra lines with a single space. The trailer text must be
valid markdown.

Update CONTRIBUTING.md with new guidelines.

Update contrib/release.sh to extract these trailers before tagging and
create a new section in CHANGELOG.md.

Extract unreleased entries in this commit to follow the new workflow.

Changelog-added: New `flagged` criteria for `:sort`.
Changelog-added: New `:send-keys` command to control embedded terminals.
Changelog-added: Account aliases now support fnmatch-style wildcards.
Changelog-fixed: `colorize` support for wildcards `?` and `*`.
Signed-off-by: Robin Jarry <robin@jarry.cc>
Acked-by: Moritz Poldrack <moritz@poldrack.dev>

0 files changed, 0 insertions, 0 deletions