docs: add JobSet API reference

[googs1025]

Fix issue: #566

How to generate documents:

root@VM-0-3-ubuntu:/home/ubuntu# cd jobset
root@VM-0-3-ubuntu:/home/ubuntu/jobset# export PATH=$PATH:/usr/local/bin/go/bin
root@VM-0-3-ubuntu:/home/ubuntu/jobset# make generate-apiref
make: go: Permission denied
cd /home/ubuntu/jobset/hack/genref/ && /home/ubuntu/jobset/bin/genref -o /home/ubuntu/jobset/site/content/en/docs/reference
I0701 10:24:47.111766 1227157 main.go:142] Parsing go packages in sigs.k8s.io/jobset/api/jobset/v1alpha2
I0701 10:24:50.923557 1227157 main.go:325] Output written to /home/ubuntu/jobset/site/content/en/docs/reference/jobset.v1alpha2.md
root@VM-0-3-ubuntu:/home/ubuntu/jobset# Connection to 43.132.121.119 closed by remote host.

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[danielvegamyhre]

Can you add a comment with a link to the documentation for this config file, so we can easily figure out how to update it later if we need to?

[googs1025]

i add this link，it allows users to query more configuration details

[googs1025]

API reference autogenerated based on this project: https://github.com/kubernetes-sigs/reference-docs/tree/master/genref

I do this PR reference from: kubernetes-sigs/kueue#1263

[danielvegamyhre]

@googs1025 I checked out this PR and previewed the output docs locally, is the {#jobset-x-k8s-io-v1alpha2-JobSet} next to the JobSet expected?

[googs1025]

@danielvegamyhre I checked the API Reference of kueue and got the same result. This is the result of the automatic document generation.
here

[danielvegamyhre]

/lgtm
/approve
Thanks!

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: danielvegamyhre, googs1025

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