docs: Fix a UI typo

Created by: serenashe

Signed-off-by: serenashe serenashe@kubesphere.io

What type of PR is this?

/kind bug /kind documentation

What this PR does / why we need it:

Fix UI typo.

Special notes for reviewers:

Please take a look, thanks. /assign @harrisonliu5

Does this PR introduced a user-facing change?

None