Fill in title, description and url labels based on the repository information.
Use repository clone URL from `github.event` instead of an undocumented variable.
Fix licenses label to follow SPDX License Expressions.
Signed-off-by: itchyny <itchyny@hatena.ne.jp>
Clarify the documentation for the dockerfile and path action inputs
including how they relate to each other.
Signed-off-by: Nick Adcock <nick.adcock@docker.com>