Move type declaration for hdkey to typescript-typings

packages/typescript-typings/types/hdkey/index.d.ts

@@ -0,0 +1,11 @@
+declare module 'hdkey' {
+    class HDNode {
+        public static fromMasterSeed(seed: Buffer): HDNode;
+        public publicKey: Buffer;
+        public privateKey: Buffer;
+        public chainCode: Buffer;
+        public constructor();
+        public derive(path: string): HDNode;
+    }
+    export = HDNode;
+}