Bug 1285253 - Change incorrect "text-anchor: left" to "start". r=jdescottes

Also fix a typo in a comment, "Rules" -> "Rulers"

MozReview-Commit-ID: Gy5k3TR9JDM

--HG--
extra : transplant_source : i%15%1B%A1L%F9%B9%23%CC%F70u%0AT%0C%B4%27m%B2%DF

devtools/server/actors/highlighters.css

@@ -293,7 +293,7 @@
   dominant-baseline: middle;
 }
 
-/* Rules highlighter */
+/* Rulers highlighter */
 
 :-moz-native-anonymous .rulers-highlighter-elements {
   shape-rendering: crispEdges;
@@ -329,7 +329,7 @@
 }
 
 :-moz-native-anonymous .rulers-highlighter-horizontal-labels > text {
-  text-anchor: left;
+  text-anchor: start;
 }
 
 :-moz-native-anonymous .rulers-highlighter-vertical-labels > text {