Wrong link to Dynamic Form docs on Zeppelin Context webpage

1. Go to https://zeppelin.apache.org/docs/0.8.0/usage/other_features/zeppelin_context.html#dynamic-forms
2. Click  on the link to "Dynamic Form.
3. 

What you expect is going to https://zeppelin.apache.org/docs/0.8.0/usage/dynamic_form/intro.html instead of https://zeppelin.apache.org/docs/0.8.0/usage/usage/dynamic_form/intro.html.