5.1.1
refactor(box): remove Bluebird.asCallback (#4379)
perf(injector): shorthand optimization (#4462)
perf(backtick_code): avoid duplicated escaping (#4478)
feat: bring up config.updated_option (#4278)
fix(filter/highlight): avoid escaping curly bracket when highlight & prismjs are disabled (#4489)
chore(deps): update hexo-front-matter from 1.0.0 to 2.0.0 (#4439)