markdown: Reset preview scroll for new files - #333464

PR classified as team-member.

⚠️ Head commit is NOT signed by a trusted team member, so the full 2-approval requirement applies. (Head commit was signed with fingerprint SHA256:SITOqsmcNrt9VCbafBaUD04K2PIPpa5sRlCjvqJMjSo, which is not listed for dmitrivMS as trusted.)

Tip: to earn the credit (−1 approval), the head commit must be signed by you with one of your own keys listed in security/trusted-signing-keys.csv. A "Verified" badge that GitHub adds to commits it creates on your behalf — web-editor edits, applied suggestions, Codespaces, API commits — does not count.

✅ Collaborator approvals: 2/2 (dbaeumer, aeschli).

✅ No newly added runnable binary files.

✅ No protected engineering system files changed.