[css-anchor-position-1] Fix abstract markup.

Author: fantasai

css-anchor-position-1/Overview.bs

@@ -12,7 +12,9 @@ Editor: Tab Atkins-Bittner, Google, http://xanthir.com/contact/, w3cid 42199
 Editor: Elika J. Etemad / fantasai, Apple, http://fantasai.inkedblade.net/contact, w3cid 35400
 Former Editor: Jhey Tompkins, Google, https://twitter.com/jh3yy, w3cid 137616
 Editor: Ian Kilpatrick, Google, w3cid 73001
-Abstract: This specification defines 'anchor positioning', where a positioned element can size and position itself relative to one or more "anchor elements" elsewhere on the page.
+Abstract: This specification defines [=anchor positioning=],
+	where a positioned element can size and position itself
+	relative to one or more “anchor elements” elsewhere on the page.
 Ignored Terms: cssText, transitions
 </pre>