Disallow invalid inline style comments in stylesheets (#9099)

res/css/views/elements/_RichText.pcss

@@ -1,6 +1,6 @@
-// XXX: bleurgh, what is this? These classes totally break the component
-// naming scheme; it's completely unclear where or how they're being used
-// --Matthew
+/* XXX: bleurgh, what is this? These classes totally break the component */
+/* naming scheme; it's completely unclear where or how they're being used */
+/* --Matthew */
 
 .mx_Markdown_BOLD {
     font-weight: bold;
@@ -13,7 +13,7 @@
     // variant seems yield better results.
 
     // compensate for Nunito italics being terrible
-    // https://github.com/google/fonts/issues/1726
+    // https://github.com/google/fonts/issues/172
     transform: skewX(-14deg);
     display: inline-block;
     */
@@ -37,8 +37,8 @@
 }
 
 .mx_Emoji {
-    // Should be 1.8rem for our default message bodies, and scale with the
-    // surrounding text
+    /* Should be 1.8rem for our default message bodies, and scale with the */
+    /* surrounding text */
     font-size: max($font-18px, 1em);
     vertical-align: bottom;
 }