Add missing Changelog entry

Jeremy Wiebe · Jeremy Wiebe · commit 721785ed86d6 · 2017-02-02T14:32:57.000-08:00
diff --git a/CHANGELOG b/CHANGELOG
@@ -1,6 +1,7 @@
 2.7.4 (February 2, 2017)
     - Add new classname prefixes to CSS documentation: `pw-` and `qa-`
     - Add links to alternative CSSComb text editor plugins
+    - Fix `lint-md` to work properly on Node.js v6+
 2.7.3
     - Temporarily disable `spaced-comment` errors, until Astro release builds comply with this rule.
 2.7.2
