Add files (#3826)

docs/guides/read-file/arraybuffer.md

@@ -0,0 +1,28 @@
+---
+name: Read a file to an ArrayBuffer
+---
+
+The `Bun.file()` function accepts a path and returns a `BunFile` instance. The `BunFile` class extends `Blob` and allows you to lazily read the file in a variety of formats. Use `.arrayBuffer()` to read the file as an `ArrayBuffer`.
+
+```ts
+const path = "/path/to/package.json";
+const file = Bun.file(path);
+
+const buffer = await file.arrayBuffer();
+```
+
+---
+
+The binary content in the `ArrayBuffer` can then be read as a typed array, such as `Uint8Array`.
+
+```ts
+const buffer = await file.arrayBuffer();
+const bytes = new Uint8Array(buffer);
+
+bytes[0];
+bytes.length;
+```
+
+---
+
+Refer to the [Typed arrays](/docs/api/binary-data#typedarray) docs for more information on working with typed arrays in Bun.