Support uploading any type of file into memos.

What's Changed

• chore: update emoji picker toggle logic by @boojack in https://github.com/usememos/memos/pull/244
• fix: mobile editor float style by @boojack in https://github.com/usememos/memos/pull/247
• fix: emoji picker position in fullscreen by @boojack in https://github.com/usememos/memos/pull/251
• feat: simple markdown parser by @boojack in https://github.com/usememos/memos/pull/252
• fix: tag regexp by @boojack in https://github.com/usememos/memos/pull/253

Full Changelog: https://github.com/usememos/memos/compare/v0.4.5...v0.5.0