[css-typed-om] Fix bikeshed fatal error regarding markdown indent.

Author: dbaron

css-typed-om/Overview.bs

@@ -318,12 +318,12 @@ The <dfn method for=StylePropertyMap>append(DOMString <var>property</var>,
     3. If {{StylePropertyMap}}’s [=property model=] contains an entry for |property|:
 
         1. If |property| is a [=list-valued property=],
-        return the list of |values| assigned to that property.
+            return the list of |values| assigned to that property.
 
         2. If |property| is not a [=list-valued property=],
-        let |values| initially be the empty [=list=] and append 
-        the |value| assigned to the |property| to this list 
-        and return |values|.
+            let |values| initially be the empty [=list=] and append 
+            the |value| assigned to the |property| to this list 
+            and return |values|.
 
     4. Else, return an empty [=list=].