docs: Update UI text.

Created by: serenashe

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

What type of PR is this?

/kind documentation

What this PR does / why we need it:

Fix wrong descriptions and placeholders.

Which issue(s) this PR fixes:

Fixes #

Special notes for reviewers:

I add a placeholder in this file. Please help me verify it, thanks.

src/utils/constants.js

Does this PR introduced a user-facing change?

None

Additional documentation, usage docs, etc.:

/assign @harrisonliu5 Please take a look, thanks.