Docs template should edit the content

The problem was described in https://github.com/apache/camel-kamelets/pull/1609. We need to change the content on the fly in order to avoid the camel-website generation to complain about variables. Escaping the variables before rendering in the website should alleviate the problem.

Review the problem described in pull request #1609 and locate the docs template involved in camel-website generation. Reproduce the complaint about variables during generation, then verify that escaping variables before website rendering prevents it without breaking the generated content.

Written by the indexing model from the issue text.