chore: import upstream snapshot with attribution

types/istextorbinary.d.ts

@@ -0,0 +1,15 @@
+/**
+ * @note For some reason the types aren't picked up from node_modules so I declared the module here
+ * with only the function that we use.
+ */
+declare module 'istextorbinary' {
+  export interface EncodingOpts {
+    /** Defaults to 24 */
+    chunkLength?: number;
+
+    /** If not provided, will check the start, beginning, and end */
+    chunkBegin?: number;
+  }
+
+  export function getEncoding(buffer: Buffer | null, opts?: EncodingOpts): 'utf8' | 'binary' | null;
+}