appview/pages/markup: make atlinks bold

Easier to spot.

Signed-off-by: Anirudh Oppiliappan <[e-mail]>

appview/pages/markup/extension/atlink.go

···
 	if entering {
 		w.WriteString(`<a href="/@`)
 		w.WriteString(n.(*AtNode).Handle)
-		w.WriteString(`" class="mention">`)
+		w.WriteString(`" class="mention font-bold">`)
 	} else {
 		w.WriteString("</a>")
 	}