logging/sign-upload.md duplicates the RPM section and leaves most pluggable-type instructions as TODO

[mailnike]

Page

content/en/logging/sign-upload.md

Problem

1. Duplicated RPM section. The table of contents lists RPM twice ([RPM](#rpm) and [RPM](#rpm-1)), backed by two identical ## RPM headings (around lines 204 and 212). The second appears to be a copy-paste artifact.
2. Unwritten sections. Several type-specific signing sections (Minisign, SSH, RPM, Alpine, TSR) have bodies that are literally TODO, so the canonical doc for signing/uploading pluggable types to Rekor is largely incomplete.

Suggested fix

• De-duplicate the RPM heading/TOC entry.
• Track and fill in the remaining TODO sections (or remove placeholders that are not yet ready).

I can help with a PR to at least de-duplicate the RPM section and tidy the TOC.