docs(agents): address Copilot review on stale RST-era conventions

Four follow-up findings from Copilot on commit e8d7e43, all valid:

- '### Formatting' bullet 'Inline code: use double backticks per RST
  convention' was carried over from the RST era. The .md sources are
  overwhelmingly single-backtick (~1900 single- vs ~80 double-backtick
  inline-code spans across docs/). Rewrite to 'single backticks in
  MyST (the canonical form). Double backticks only inside
  {eval-rst} blocks and _include/*.txt snippets, per RST convention.'

- '### RST heading hierarchy' section read like a general authoring
  rule. Add a preface scoping it explicitly to RST contexts
  (_include/*.txt and {eval-rst} blocks) and noting that canonical
  MyST pages use ATX (# / ## / ...) headings. Reword the post-block
  prose to 'every embedded RST snippet that introduces a title'
  instead of 'every RST file'.

- '### `.. TODO::` markers' heading and prose described the RST
  form only. The .md sources use `{todo}` fenced directives
  exclusively (6 triple-backtick + 1 colon-fenced occurrences across
  docs/, zero `.. TODO::` in .md). Rename the section to
  '`{todo}` markers', describe the MyST fenced form first, and
  mention the RST form only for RST contexts.

- Drop the '% stop_vyoslinter' / '% start_vyoslinter' markers I
  added around the '8.8.8.8' DNS example bullet under
  '### IP addresses'. Replace the literal IP with a description-only
  example ('a DNS server's address in a DNS forwarder example, or an
  upstream peer's address in an EBGP example'). The bullet still
  illustrates the rule (real public IPs need suppression) without
  rendering bare '% stop_vyoslinter' lines in GitHub views.

Local doc-linter still exits 0 on AGENTS.md and README.md.

0 files changed, 0 insertions, 0 deletions