Update src/doc/contrib/src/implementation/schemas.md

Co-authored-by: Weihang Lo <[email protected]>

src/doc/contrib/src/implementation/schemas.md

@@ -16,7 +16,7 @@ Generally,
   - Also, we can always switch to always outputting the fields but its harder to stop outputting them
   - `#[serde(skip_serializing_if = "Default::default")]` should be applied liberally
 - For output, prefer [jsonlines](https://jsonlines.org/) as it allows streaming output and flexibility to mix content (e.g. adding diagnostics to output that didn't prevously have it
-- `deny_unknown_fields` should not be used to allow evolution of formats, including feature gating
+- `#[serde(deny_unknown_fields)]` should not be used to allow evolution of formats, including feature gating
 
 ## Schema Evolution Strategies