v0.8.0

What's Changed

• feat: add value_as_number to css-node by @bartveneman in #53
• perf: make is_vendor_prefixed() lazy evaluation by @bartveneman in #57
• perf: reorganize arena to save 4 8 bytes (20%) by @bartveneman in #59
• BREAKING: rename offset to start; add end by @bartveneman in #60

Full Changelog: v0.7.3...v0.8.0