Merge pull request rails#51724 from akhilgkrishnan/fix-document-css

Fix guides styling issue on light mode [ci skip]

Fixes: rails#51723

Author: carlosantoniodasilva

guides/assets/stylesrc/_main.scss

@@ -278,7 +278,6 @@ body.guide {
     line-height: 1.5;
     margin: 1em 0;
     overflow: auto;
-    color: #222;
   } // pre, code
 
   p code, ul code {

guides/assets/stylesrc/highlight.scss

@@ -71,6 +71,7 @@
   .n   { color: #f8f8f2; } /* Name */
   .o   { color: #ff699b; } /* Operator */
   .p   { color: #f8f8f2; } /* Punctuation */
+  .pi  { color: #c74646; } /* Punctuation.Indicator */
   .cm  { color: #b4b4b3; } /* Comment.Multiline */
   .cp  { color: #b4b4b3; } /* Comment.Preproc */
   .c1  { color: #b4b4b3; } /* Comment.Single */