upgrade to docify v0.2.4 (#1653)
Upgrades to docify v0.2.4 which adds support for exporting trait and impl items in addition to regular items. This fixes @liamaharon's https://github.com/sam0x17/docify/issues/9 issue. See the release notes for more information: https://github.com/sam0x17/docify/releases/tag/v0.2.4