Update src/content/docs/cache/how-to/cache-keys.mdx

Author: angelampcosta

src/content/docs/cache/how-to/cache-keys.mdx

@@ -91,7 +91,7 @@ Headers control which headers go into the Cache Key. Similar to Query String, yo
 
 When you include a header, the header value is included in the Cache Key. For example, if an HTTP request contains an HTTP header like `X-Auth-API-key: 12345`, and you include the `X-Auth-API-Key header` in your Cache Key Template, then `12345` appears in the Cache Key.
 
-In the **Include headers and selected values** section, you can add header names and their values to the cache key. For custom headers, values are optional, but for the following restricted headers, you must include one to ten specific values:
+In the **Include headers and selected values** section, you can add header names and their values to the cache key. For custom headers, values are optional, but for the following restricted headers, you must include one to 10 specific values:
 
   * `accept`
   * `accept-charset`