[Doc] clarify retry loop

[kaisecheng]

The retry policy confuses users mainly due to the unclear boundary of retry_failed and automatic_retries.

This PR explains retry_failed set to false does not affect the number of retries in lib level

[karenzone]

I left some comments wrt formatting.

Now

Here's how it renders now:

Proposed

We can make it easier for users to scan and parse with some formatting tweaks (as suggested inline):

Let me know what you think and if you would like to discuss. Thanks for your work on this.

[karenzone]

Also, what do you think about noting in option descriptions which retry type they apply to?

[kaisecheng]

Also, what do you think about noting in option descriptions which retry type they apply to?

If we have some markers to make it clear which options belong to which types, it would be very good. But now I only see verbose messages, so my new commits give a pointer (see Retry Policy...) to all four options. I hope these hints are clear enough.

[kaisecheng]

@karenzone Wow! The new format is so amazing! You raise it to the next level 🚀

Committed all your suggestion. I copy some important information from "Retry Policy" session to those four options, make a pointer from the options to the "Retry Policy", and update some wording. Please have a look to the last commit. Thank you.