readme: Update with new serializer instructions

README.md

@@ -26,13 +26,46 @@ To update the benchmark report:
 go test -tags genreport -run TestGenerateReport
 ```
 
+To update the benchmark report with using a longer run benchmark (to get more
+accurate results):
+
+```bash
+go test -tags genreport -run TestGenerateReport -benchtime 10s -timeout 1h
+```
+
 ## Recommendation
 
 If correctness and interoperability are the most
 important factors [JSON](http://golang.org/pkg/encoding/json/) or [Protobuf](https://google.golang.org/protobuf) are your best options.
 
 But as always, make your own choice based on your requirements.
 
+## Adding New Serializers
+
+Review the following instructions _before_ opening the PR to add a new
+serializer:
+
+- Create all the required serializer code in `internal/<short serializer name>`.
+- Add an entry to the serializer in [benchmarks.go](benchmarks.go).
+- If the serializer supports both reusing/not reusing its marshalling buffer:
+  - Add both a `serializer` and `serializer/reuse` entries, each one
+    respectively reusing/not reusing the resulting marshalling buffer. Set the
+    `BufferReuseMarshal` flag accordingly.
+- If the serializer supports both safe and unsafe string unmarshalling:
+  - Add both a `serializer` and `serializer/unsafe` entries, each one
+    respectively unmarshalling into safe and unsafe strings. Set the
+    `UnsafeStringUnmarshal` flag accordingly.
+- If the serializer supports both marshalling buffer reuse and unsafe string
+  unmarshalling, merge both options into a single `serializer/unsafe_reuse`
+  entry (check the baseline serializer for an example).
+- Regenerate the report by running:
+
+```
+go test -tags genreport -run TestGenerateReport
+```
+
+- **Include the updated report data in your PR**
+
 ## Data
 
 The data being serialized is the following structure with randomly generated values: