[cleanup] Remove legacy preview instructions
@@ -75,7 +75,7 @@ This change added tests and can be verified as follows:
<!-- DO NOT REMOVE THIS SECTION. CHECK THE PROPER BOX ONLY. -->
-- [ ] `doc` <!-- Your PR contains doc changes. Please attach the local preview screenshots (run `sh start.sh` at `pulsar/site2/website`) to your PR description, or else your PR might not get merged. -->
+- [ ] `doc` <!-- Your PR contains doc changes. -->
- [ ] `doc-required` <!-- Your PR changes impact docs and you will update later -->
- [ ] `doc-not-needed` <!-- Your PR changes do not impact docs -->
- [ ] `doc-complete` <!-- Docs have been already added -->
