[DOCS] Update branch attribute to fix doc links (#1577)

Co-authored-by: debadair <debadair@elastic.co>

docs/connecting.asciidoc

@@ -61,11 +61,12 @@ const client = new Client({
 ==== ApiKey authentication
 
 You can use the 
-https://www.elastic.co/guide/en/elasticsearch/reference/7.16/security-api-create-api-key.html[ApiKey] 
+{ref-7x}/security-api-create-api-key.html[ApiKey] 
 authentication by passing the `apiKey` parameter via the `auth` option. The 
 `apiKey` parameter can be either a base64 encoded string or an object with the 
 values that you can obtain from the 
-https://www.elastic.co/guide/en/elasticsearch/reference/7.16/security-api-create-api-key.html[create api key endpoint].
+{ref-7x}/security-api-create-api-key.html[create api key endpoint].
+
 
 NOTE: If you provide both basic authentication credentials and the ApiKey 
 configuration, the ApiKey takes precedence.

docs/index.asciidoc

@@ -1,6 +1,6 @@
 = Elasticsearch JavaScript Client
 
-:branch: 7.x
+:branch: 7.16
 include::{asciidoc-dir}/../../shared/attributes.asciidoc[]
 
 include::introduction.asciidoc[]