v2.8.0

• Allow specifying subdirectory with default git context (#531)
• Add cgroup-parent, shm-size, ulimit inputs (#501)
• Don't set outputs if empty or nil (#470)
• docs: example to sanitize tags with metadata-action (#476)
• docs: wrong syntax to sanitize repo slug (#475)
• docs: test before pushing your image (#455)
• readme: remove v1 section (#500)
• ci: virtual env file system info (#510)
• dev: update workflow (#499)
• Bump @actions/core from 1.5.0 to 1.6.0 (#160)
• Bump ansi-regex from 5.0.0 to 5.0.1 (#469)
• Bump tmpl from 1.0.4 to 1.0.5 (#465)
• Bump csv-parse from 4.16.0 to 4.16.3 (#451 #459)