Generate a changelog/release notes using Conventional Commit standards

gistfile1.txt

# one-liner
if [ -z "$(git tag -l --sort=v:refname | tail -1)" ]; then git log --oneline --all; else git log --oneline $(git tag -l --sort=v:refname | tail -1)..$(git rev-parse --abbrev-ref HEAD); fi | awk '$2 ~ /:/' | sort -sk 2,2 | awk 'BEGIN {print "## Changelog"} NR == 1 {print "- " $0; type = gensub(/(\w+).*:/, "\\1", 1, $2)} NR > 1 && $2 !~ type {print ""} NR > 1 {print "- " $0; type = gensub(/(\w+).*:/, "\\1", 1, $2)}'

# nicely formatted
if [ -z "$(git tag -l --sort=v:refname | tail -1)" ]
then
  git log --oneline --all
else
  git log --oneline $(git tag -l --sort=v:refname | tail -1)..$(git rev-parse --abbrev-ref HEAD)
fi | awk '$2 ~ /:/' \
| sort -sk 2,2 \
| awk 'BEGIN {print "## Changelog"}
       NR == 1 {print "- " $0; type = gensub(/(\w+).*:/, "\\1", 1, $2)}
       NR > 1 && $2 !~ type {print ""}
       NR > 1 {print "- " $0; type = gensub(/(\w+).*:/, "\\1", 1, $2)}'

Edited to avoid grouping by scope unnecessarily