[synthetics] Align CLI and config docs

[colleenmcginnis]

Fixes #3030

Updates the Use the Synthetics CLI and Configure Synthetics projects docs to including:

• Inventory the options in both and make sure all options line up.
• Link between CLI and config docs.
• Update the example config to match the latest config template.
  • Add a note that env is the environment users are pushing from not the environment where monitors will run.

cc @paulb-elastic

[github-actions]

A documentation preview will be available soon:

• 📚 HTML diff
• 📙 Observability Guide

[vigneshshanmugam]

LGTM, can we also add tags/alert as part of the monitor options? Release notes has some details on how its done - https://github.com/elastic/synthetics/releases

[colleenmcginnis]

LGTM, can we also add tags/alert as part of the monitor options? Release notes has some details on how its done - https://github.com/elastic/synthetics/releases

Done in #3087.

[vigneshshanmugam]

LGTM

[mergify]

This pull request is now in conflict. Could you fix it @colleenmcginnis? 🙏
To fixup this pull request, you can check out it locally. See documentation: https://help.github.com/articles/checking-out-pull-requests-locally/

git fetch upstream
git checkout -b issue-3030 upstream/issue-3030
git merge upstream/main
git push upstream issue-3030

[paulb-elastic]

These are great updates, thank you @colleenmcginnis, it really enhances the docs and shows the options available

LGTM