docs: link to the style guide entry for keyed v-for (#1164)

Author: skirtles-code

src/guide/list.md

@@ -127,7 +127,7 @@ To give Vue a hint so that it can track each node's identity, and thus reuse and
 </div>
 ```
 
-It is recommended to provide a `key` attribute with `v-for` whenever possible, unless the iterated DOM content is simple, or you are intentionally relying on the default behavior for performance gains.
+[It is recommended](/style-guide/#keyed-v-for-essential) to provide a `key` attribute with `v-for` whenever possible, unless the iterated DOM content is simple, or you are intentionally relying on the default behavior for performance gains.
 
 Since it's a generic mechanism for Vue to identify nodes, the `key` also has other uses that are not specifically tied to `v-for`, as we will see later in the guide.