BPRT sync: point the page and docstrings at static/Sync-BPRT.ps1

Follow-up to 92f1e62, which moved the file but missed these references.

webapp/views/bprt_sync.py

@@ -1,6 +1,6 @@
 """Updates > BPRT: bring the vendor bulk-enroll folder over from the work PC.
 
-The work PC runs scripts/windows/Sync-BPRT.ps1, which reads manifest.json
+The work PC runs Sync-BPRT.ps1 (webapp/static, downloadable here), which reads manifest.json
 here, uploads the new and changed files over SSH into BPRT-incoming/<batch>/
 and points the user at this page. Here a batch is validated, its diff shown,
 and activated (a new BPRT built from hard links and swapped in by rename);