Adds cert-management/istio-csr task documentation for cert-manager integration

[JoshVanL]

This PR adds a task for using istio-csr which enables integration with cert-manager. cert-manager has support for many external CA issuers, which can be used to setup and sign all certificates in Istio.

Let me know if this is appropriate to add in! Happy to have a go at setting up some tests for this.

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

[istio-policy-bot]

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[google-cla[bot]]

Thanks for your pull request. It looks like this may be your first contribution to a Google open source project (if not, look below for help). Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

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[istio-testing]

Hi @JoshVanL. 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/test-infra repository.

[craigbox]

/ok-to-test

Waiting on suggested fix from Eric and CLA

[JoshVanL]

@googlebot I signed it!

[google-cla[bot]]

Thanks for your pull request. It looks like this may be your first contribution to a Google open source project (if not, look below for help). Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

:memo: Please visit https://cla.developers.google.com/ to sign.

Once you've signed (or fixed any issues), please reply here with @googlebot I signed it! and we'll verify it.

---

What to do if you already signed the CLA

Individual signers

• It's possible we don't have your GitHub username or you're using a different email address on your commit. Check your existing CLA data and verify that your email is set on your git commits.

Corporate signers

• Your company has a Point of Contact who decides which employees are authorized to participate. Ask your POC to be added to the group of authorized contributors. If you don't know who your Point of Contact is, direct the Google project maintainer to go/cla#troubleshoot (Public version).
• The email used to register you as an authorized contributor must be the email used for the Git commit. Check your existing CLA data and verify that your email is set on your git commits.
• The email used to register you as an authorized contributor must also be attached to your GitHub account.

ℹ️ Googlers: Go here for more info.

[googlebot]

Thanks for your pull request. It looks like this may be your first contribution to a Google open source project (if not, look below for help). Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

:memo: Please visit https://cla.developers.google.com/ to sign.

Once you've signed (or fixed any issues), please reply here with @googlebot I signed it! and we'll verify it.

---

What to do if you already signed the CLA

Individual signers

• It's possible we don't have your GitHub username or you're using a different email address on your commit. Check your existing CLA data and verify that your email is set on your git commits.

Corporate signers

• Your company has a Point of Contact who decides which employees are authorized to participate. Ask your POC to be added to the group of authorized contributors. If you don't know who your Point of Contact is, direct the Google project maintainer to go/cla#troubleshoot (Public version).
• The email used to register you as an authorized contributor must be the email used for the Git commit. Check your existing CLA data and verify that your email is set on your git commits.
• The email used to register you as an authorized contributor must also be attached to your GitHub account.

ℹ️ Googlers: Go here for more info.

[JoshVanL]

@googlebot I signed it!

[istio-testing]

@JoshVanL: The following test failed, say /retest to rerun all failed tests:

Test name	Commit	Details	Rerun command
lint_istio.io	d0f9051ad2948bbd60a4cccb349b00755f5f71c3	link	/test lint_istio.io

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]

/retest

[istio-testing]

@JoshVanL: 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_default_istio.io	d0f9051ad2948bbd60a4cccb349b00755f5f71c3	link	true	/test doc.test.profile_default
gencheck_istio.io	d0f9051ad2948bbd60a4cccb349b00755f5f71c3	link	true	/test gencheck
lint_istio.io	d0f9051ad2948bbd60a4cccb349b00755f5f71c3	link	true	/test lint

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.