style: the inline-wrap icon shows the object in the line

Three bare lines said nothing and read the same at any size. It now draws
the box on the text baseline like the floating toolbar's glyph, with the
outlined object the other three wrap icons use.

src/lib/components/ribbon/icons.ts

@@ -70,10 +70,13 @@ export const STROKED = {
   alignMiddle: ['M2 8h12', 'M8 2.5v3M8 10.5v3'],
   alignBottom: ['M2 13h12', 'M8 3.5v7M5.5 8 8 10.5 10.5 8'],
   cellMargins: ['M2 2.5h12v11H2z', 'M4.5 5h7v6h-7z'],
-  wrapInline: ['M2 4h12M2 8h12M2 12h12'],
+  // The box sits on the text baseline, a line running to it from either side.
+  wrapInline: ['M2 3h12', 'M6 5.5h4.5v5.5H6z', 'M2 11h3.5M11 11h3', 'M2 13.5h12'],
   wrapLeft: ['M2 3.5h6v9H2z', 'M9.5 4.5h4.5M9.5 7h4.5M9.5 9.5h4.5M9.5 12h4.5'],
   wrapRight: ['M8 3.5h6v9H8z', 'M2 4.5h4.5M2 7h4.5M2 9.5h4.5M2 12h4.5'],
   wrapTopBottom: ['M4 6.5h8v3H4z', 'M2 3h12M2 13h12'],
+  // A capital T beside an arrow running down: the text sets vertically.
+  textDirection: ['M3 3.75h6M6 3.75v8.5', 'M12.5 4v7.5M10.9 10l1.6 1.6 1.6-1.6'],
   toc: ['M2 3h6M2 6.5h5M2 10h6M2 13.5h4', 'M11 3h3M10 6.5h4M11 10h3M10 13.5h4'],
   tocLevels: ['M2.5 3.5h11M4.5 7h9M6.5 10.5h7M8.5 14h5'],
   caption: ['M2 2.5h12v7.5H2z', 'M2 13h7'],