:doc: doc and demo for "Font for eastAsia"

docs/usage/styling-with-js.md

@@ -26,7 +26,7 @@ const name = new TextRun({
 -   `emphasisMark({type="dot"})`: Set the emphasis mark style
 -   `color(color)`: Set the text color, using 6 hex characters for RRGGBB (no leading `#`)
 -   `size(halfPts)`: Set the font size, measured in half-points
--   `font(name)`: Set the run's font
+-   `font(name)` or `font({ascii, cs, eastAsia, hAnsi, hint})`: Set the run's font
 -   `style(name)`: Apply a named run style
 -   `characterSpacing(value)`: Set the character spacing adjustment (in TWIPs)