fix: fix storageclass doc link

Created by: xuliwenwenwen

Signed-off-by: xuliwenwenwen liwenxu@yunify.com

What type of PR is this?

/kind bug

What this PR does / why we need it:

Which issue(s) this PR fixes:

Fixes #kubesphere/kubesphere#3730

Special notes for reviewers:

Additional documentation, usage docs, etc.: