## Summary
The `<` in a `created_at<` condition is the comparison operator, but in
three places it had been paired with a closing `>` as if it opened a
`<placeholder>` bracket:
- **NIP-OA** clause list: `created_at<unix-timestamp>` →
`created_at<unix-timestamp`
- **NIP-OA** satisfaction rule: `created_at<t>` → `created_at<t`
- **NIP-GS** "Conditions in Git Context": `created_at<t>` →
`created_at<t` (line 437 of the same file already used the correct form)
This matches the `created_at>...` forms used alongside them, which never
carried a closing bracket. Also normalizes the NIP-OA headings to ATX
style and pretty-prints the signed-event JSON example for readability.
## Verification
Docs-only change. The NIP-OA test vectors are untouched and were
re-verified by recomputing them: the preimage SHA-256, `tag-bytes-hex`,
and the signed-event `id` all still match the documented values.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Signed-off-by: zmeyer44 <zmmeyer44@gmail.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
