chore: add cors method option

[okaybase]

Please answer these questions before submitting a pull request, or your PR will get closed.

Why submit this pull request?

• Bugfix
• New feature provided
• Improve performance
• Backport patches

What changes will this PR take into?

Other options can not use * when set allow_credential = true, so add ** option for allow_methods.

Related issues

fix/resolve:

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

[netlify]

✔️ Deploy Preview for apisix-dashboard ready!

🔨 Explore the source changes: 00626fe

🔍 Inspect the deploy log: https://app.netlify.com/sites/apisix-dashboard/deploys/612cfe1c032eb00008d6226c

😎 Browse the preview: https://deploy-preview-2103--apisix-dashboard.netlify.app/

[liuxiran]

Hi @okaybase , this pr depends on updating the schema.json to the latest right?

[okaybase]

Hi @okaybase , this pr depends on updating the schema.json to the latest right?

Hi @liuxiran , don't need to sync the latest schema.json, this pr just fix/add some tips and add an method option.

[liuxiran]

Hi @okaybase , this pr depends on updating the schema.json to the latest right?

Hi @liuxiran , don't need to sync the latest schema.json, this pr just fix/add some tips and add an method option.

ok, thanks for your Instructions