* Add new color patterns algorithm
* Add color palettes
* update other colors
* fix gray color
* update more tint/shade to colorPalette
* new font color
* Update doc for new color system
* improve doc style
+ add `getSuggestionContainer` callback function, which allow users modify the
container element of suggestions dropdown.
+ the suggestions dropdown will mount on `document.body` defaultly, instead of
on editor.
+ close#3588