Update refdocs to use markdown links and standardize HTTP/2 notation in master

[AdeshGhadage]

Converted inline URLs to markdown format in refdocs. Standardized "HTTP2" to "HTTP/2". Changes made in the master branch of istio/api. This aligns with issue #16102.

[istio-policy-bot]

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[istio-testing]

Hi @AdeshGhadage. Thanks for your PR.

I'm waiting for a istio member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[zirain]

/ok-to-test

[craigbox]

Please bring the URL changes from #3431 into this PR and we can proceed. Check each URL, as the first one I tried was 404.

[istio-testing]

@AdeshGhadage: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
release-notes_api	f11bc20	link	false	/test release-notes

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository. I understand the commands that are listed here.