optimize the experience of the short note editor

[ahonn]

The style of the short note editor is a bit rough and needs some optimization for a better user experience. This includes:

• Text description of the unified toolbar (capitalization, text style, etc.)
• The emoji floating window has a style change when it is first opened (a narrow vertical line is displayed when the emoji is not loaded)
• The editor does not automatically collapse when it loses focus (onblur)