Add toc

src/engine/cancun.md

@@ -9,8 +9,23 @@ This specificaiton is based on and extends [Engine API - Shanghai](./shanghai.md
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+- [Structures](#structures)
+  - [ExecutionPayloadV3](#executionpayloadv3)
+  - [BlobsBundleV1](#blobsbundlev1)
+- [Methods](#methods)
+  - [engine_newPayloadV3](#engine_newpayloadv3)
+    - [Request](#request)
+    - [Response](#response)
+    - [Specification](#specification)
+  - [engine_getPayloadV3](#engine_getpayloadv3)
+    - [Request](#request-1)
+    - [Response](#response-1)
+    - [Specification](#specification-1)
+
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+## Structures
+
 ### ExecutionPayloadV3
 
 This structure has the syntax of [`ExecutionPayloadV2`](./shanghai.md#executionpayloadv2) and append two new fields: `dataGasUsed` and `excessDataGas`.