v0.9.0

It's the first release with Rust codebase, so basically everything is new.

Generated release note down here.

What's Changed

• bump hudhook to mainline head by @ruby3141 in #6
• use hack to use em size for font by @ruby3141 in #7
• implement autosave by @ruby3141 in #8

Full Changelog: v0.1.1...v0.9.0