Update README

bindings/node.js/README.md

@@ -1,19 +1,50 @@
 This directory contains the code necessary to generate NodeJS bindings for C-KZG.
 
-First, install:
+```js
 
-```
-yarn install
+  loadTrustedSetup: (filePath: string) => SetupHandle;
+
+  freeTrustedSetup: (setupHandle: SetupHandle) => void;
+
+  blobToKzgCommitment: (blob: Blob, setupHandle: SetupHandle) => KZGCommitment;
+
+  computeAggregateKzgProof: (
+    blobs: Blob[],
+    setupHandle: SetupHandle
+  ) => KZGProof;
+
+  verifyAggregateKzgProof: (
+    blobs: Blob[],
+    expectedKzgCommitments: KZGCommitment[],
+    kzgAggregatedProof: KZGProof,
+    setupHandle: SetupHandle
+  ) => boolean;
 ```
 
-Then build
+Spec: https://github.com/ethereum/consensus-specs/blob/dev/specs/eip4844/polynomial-commitments.md
 
-```
-make build
+`npm install -g yarn` if you don't have it.
+
+Install the blst submodule
+
+```sh
+git submodule update --init
 ```
 
-Run the TypeScript tests
+Build blst and c_kzg_4844.c
 
 ```
-yarn test
+cd src && make blst lib
+```
+
+Generate NodeJS bindings and run the TypeScript tests against them
+
+```sh
+cd ../bindings/node.js && yarn install && make test
+```
+
+After doing this once, you can re-build (if necessary) and re-run the tests with
+
+```sh
+make build test
 ```