v1.7.0

Minor release: parsing hardening for pure substitutions and heredocs, plus a post-cd prompt fix.

• feat: resolve whitelisted pure substitutions in file operands by @karlkfi in #86
• feat: parse heredoc bodies as opaque data before shlex by @karlkfi in #87
• fix: name resolved absolute paths in post-cd prompts; correct untracked-cd docs by @karlkfi in #88

Full Changelog: v1.6.0...v1.7.0