[Refactor] istio.io security concept page - Authn

[xulingqing]

Preview Link: https://deploy-preview-10157--preliminary-istio.netlify.app/latest/docs/concepts/security/

Main Changes:

1. Merge Istio identity and Identity and certificate management to Istio identity and certificate management
2. Delete TLS cipher suites details and move to reference
3. Move Permissive mode to Authn Task as a new task
4. Merge Authentication architecture to authn introduction
5. Delete Policy storage and summarized in authn introduction
6. Delete Selector field, use 1 policy to give a brief introduction to selector. And move the description to reference/config/security
7. Prune extra examples of peer authentication
8. Delete Principals
9. Move Updating authentication policies

• Configuration Infrastructure
• Docs
• Installation
• Networking
• Performance and Scalability
• Policies and Telemetry
• Security
• Test and Release
• User Experience
• Developer Infrastructure

[istio-policy-bot]

😊 Welcome! This is either your first contribution to the Istio documentation repo, or
it's been awhile since you've been here. A few things you should know:

• You can learn about how we write and maintain documentation, about our style guidelines,
  and about all the available web site features by visiting Contributing to the Docs.

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• We care about quality, so we've put in place a number of checks to ensure our documentation
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• Once your changes are accepted and merged into the repository, they will initially show up
  on https://preliminary.istio.io. The changes will be published to https://istio.io
  the next time we do a major release (which typically happens every 3 months or so).

Thanks for contributing!

Courtesy of your friendly welcome wagon.

[istio-testing]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[istio-testing]

@xulingqing: PR needs rebase.

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/test-infra repository.

[istio-testing]

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

Test name	Commit	Details	Required	Rerun command
doc.test.profile_demo_istio.io	728f966	link	true	/test doc.test.profile_demo
doc.test.profile_none_istio.io	728f966	link	true	/test doc.test.profile_none
doc.test.multicluster_istio.io	728f966	link	true	/test doc.test.multicluster
doc.test.profile_default_istio.io	728f966	link	true	/test doc.test.profile_default
doc.test.profile_minimal_istio.io	728f966	link	true	/test doc.test.profile_minimal
doc.test.profile-default_istio.io	728f966	link	true	/test doc.test.profile-default
doc.test.profile-none_istio.io	728f966	link	true	/test doc.test.profile-none
doc.test.profile-minimal_istio.io	728f966	link	true	/test doc.test.profile-minimal
doc.test.profile-demo_istio.io	728f966	link	true	/test doc.test.profile-demo

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/test-infra repository. I understand the commands that are listed here.

[craigbox]

@xulingqing and @justinpettit, any interest in finishing this other one off?