Update the Integrations doc guidelines to reflect the new template

[alaudazzi]

This PR:

• Updates the https://www.elastic.co/docs/extend/integrations/documentation-guidelines to reflect the new doc template
• Simplifies the wording to make the page more readable.

[github-actions]

🔍 Preview links for changed docs

• docs/extend/documentation-guidelines.md

[alaudazzi]

@kgeller @mjwolf @haetamoudi
A few points to consider:

• I removed the Template and Examples sections -- I find they overload the page and generate some noise. If we think they are useful, we can put them back.
• We probably need to update this page as well https://github.com/elastic/elastic-package/blob/main/docs/howto/add_package_readme.md

[kgeller]

• We probably need to update this page as well https://github.com/elastic/elastic-package/blob/main/docs/howto/add_package_readme.md

Great call out! I'll add an issue today for that, and make sure there aren't any other pages in that folder that we're missing

I forgot we already have updated that file with our first elastic-package change here. All the other files in the folder aren't relevant. Skipping the new issue 👍

[kgeller]

LGTM 👍

[muthu-mps]

The performance and scaling depends on the users underlying infrastructure. Currently, I am noticing the ingest architecture is shared for one of the integrations. Is this an optional section in the document?

[alaudazzi]

Ideally, all sections should be included where applicable and if there is relevant content.

[kpollich]

LGTM 🚀