comment out broken file path

Author: DavidWells

packages/core/_tests/fixtures/md/transform-file/shift-headers.md

@@ -22,7 +22,7 @@ I'm imagining a world where your code AST is parsed and you can automatically in
 One day...
 
 <!-- docs FILE
-  src="./x.md"
+  // src="./x.md"
   shiftHeaders=-1
   removeLeadingH1
 -->