[DOC] Add yml highlight and copy button to pipeline docs and fix config navigation for Data Prepper

[vagimeli]

What do you want to do?

• Request a change to existing documentation
• Add new documentation
• Report a technical problem with the documentation
• Other

Tell us about your request. Provide a summary of the request.

• Looking at the Data Prepper section, none of the yaml snippets have the yaml highlighter or copy button added.
• The configuration directory seems unnecessary. Just want to flag this for a future fix. This just makes the link longer (and shorter links are preferable for SEO). We can fix that by removing the configuration folder and adding redirects from the old link to the new link in all files under the pipelines directory.

*Version: List the OpenSearch version to which this issue applies, e.g. 2.14, 2.12--2.14, or all.

Current version

What other resources are available? Provide links to related issues, POCs, steps for testing, etc.