📖 docs: add remaining Quick Start part with patterns and troubleshooting

[RayyanSeliya]

Summary

Completes the Quick Start Guide by adding practical patterns, comprehensive troubleshooting, and enhanced navigation.

Added sections:

• Common use case patterns (dev teams, environments, SaaS)
• Troubleshooting guide (5 scenarios with solutions)
• Persona-based next steps navigation
• Getting help resources
• Achievement summary

Related issue(s)

Part of the documentation restructuring for kflex.dev docsite development.

[kubestellar-prow]

[APPROVALNOTIFIER] This PR is NOT APPROVED

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[kubestellar-prow]

Hi @RayyanSeliya. Thanks for your PR.

I'm waiting for a kubestellar 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.

Details

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.

[clubanderson]

⚠️ Unit test failing due to stale base branch

This PR targets the doc-kubeflex branch which hasn't been updated since October 2025 and is significantly behind main.

The prow unit test is failing because the base branch is missing recent CI/workflow changes.

To fix: Either:

1. Merge main into doc-kubeflex branch
2. Or rebase this PR onto main directly

cc @kubestellar/kubeflex-maintainers

[clubanderson]

/ok-to-test

[kubestellar-prow]

@RayyanSeliya: 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
pull-kubestellar-kubeflex-test-unit	0f4b5d4	link	true	/test pull-kubestellar-kubeflex-test-unit

Full PR test history

Details

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.