docs: fix timeouts in the health check example and update links for config-default.yaml reference

[kayx23]

Type of change:

• Bugfix
• New feature provided
• Improve performance
• Backport patches
• Documentation
• Refactor
• Chore
• CI/CD or Tests

What this PR does / why we need it:

Encountered errors using the correct example.

Error from server (BadRequest): error when creating "upstreams.yaml": ApisixUpstream in version "v2" cannot be handled as a ApisixUpstream: strict decoding error: unknown field "spec.healthCheck.passive.unhealthy.timeout"

spec.healthCheck.active.timeout: Invalid value: "string": spec.healthCheck.active.timeout in body must be of type number: "string"

This PR fixes the example.

Pre-submission checklist:

• Did you explain what problem does this PR solve? Or what new features have been added?
• Have you added corresponding test cases?
• Have you modified the corresponding document?
• Is this PR backward compatible? If it is not backward compatible, please discuss on the mailing list first

[pottekkat]

Could you check the lint error for the broken link?

It seems like the config-default.yaml file was moved to https://github.com/apache/apisix/blob/master/conf/config.yaml.example and now we define the default config in a Lua file: apache/apisix#11343

It should be a find and replace fix and since the scope of this PR isn't too big, we can fix it here itself.

[github-actions]

This pull request has been marked as stale due to 60 days of inactivity. It will be closed in 30 days if no further activity occurs. If you think that's incorrect or this pull request should instead be reviewed, please simply write any comment. Even if closed, you can still revive the PR at any time or discuss it on the [email protected] list. Thank you for your contributions.

[github-actions]

This pull request has been marked as stale due to 60 days of inactivity. It will be closed in 30 days if no further activity occurs. If you think that's incorrect or this pull request should instead be reviewed, please simply write any comment. Even if closed, you can still revive the PR at any time or discuss it on the [email protected] list. Thank you for your contributions.