adding zkevm endpoints

Author: kmurphypolygon

docs/zkEVM/api/json-rpc.md

@@ -0,0 +1,6 @@
+---
+hide:
+- toc
+---
+
+<embed type="text/html" src="https://playground.open-rpc.org/?schemaUrl=https://raw.githubusercontent.com/0xPolygonHermez/zkevm-node/blob/develop/jsonrpc/endpoints_zkevm.openrpc.json?uiSchema[appBar][ui:input]=false&uiSchema[appBar][ui:splitView]=false" width="100%" height="1000px">

mkdocs.yml

@@ -219,6 +219,8 @@ nav:
           - Basic Syntax: zkEVM/spec/zkasm/basic-syntax.md
           - Examples: zkEVM/spec/zkasm/examples.md
         - EVM vs. zkEVM: zkEVM/spec/evm-differences.md
+      - API: 
+        - JSON RPC endpoints: zkEVM/api/json-rpc.md
       - Concepts:
         - Concepts: zkEVM/concepts/index.md
         - EVM basics: zkEVM/concepts/evm-basics.md