docs: clean up config discovery docs and make it consistent

[agrawroh]

Description

This PR have some cleanup in config discovery proto docs for consistency. We are using the note annotations and the backticks inconsistently throughout right now.

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Commit Message: docs: clean up config discovery docs and make it consistent Additional Description: Minor clean up for added clarity on the config discovery docs. Risk Level: N/A Testing: N/A Docs Changes: N/A Release Notes: N/A

[repokitteh-read-only[bot]]

Docs for this Pull Request will be rendered here:

https://storage.googleapis.com/envoy-pr/39918/docs/index.html

The docs are (re-)rendered each time the CI envoy-presubmit (precheck docs) job completes.

:cat:

Caused by: https://github.com/envoyproxy/envoy/pull/39918 was opened by agrawroh.

see: more, trace.

[repokitteh-read-only[bot]]

CC @envoyproxy/api-shepherds: Your approval is needed for changes made to (api/envoy/|docs/root/api-docs/). envoyproxy/api-shepherds assignee is @adisuissa CC @envoyproxy/api-watchers: FYI only for changes made to (api/envoy/|docs/root/api-docs/).

:cat:

Caused by: https://github.com/envoyproxy/envoy/pull/39918 was opened by agrawroh.

see: more, trace.

[adisuissa]

Oops, CI failure seems relevant. /wait