Add examples

examples/ecdh-wraps-ecdh.test.ts

@@ -0,0 +1,14 @@
+import {expect} from 'bun:test'
+
+import {PrivateWrap} from '../index'
+
+const key_wraps = await PrivateWrap.gen_keypair()
+const key_wrapped = await PrivateWrap.gen_keypair()
+
+const cipher = await PrivateWrap.encrypt(key_wrapped.privateKey, key_wraps.publicKey)
+const box = await cipher.toString()
+const unbox = await PrivateWrap.fromString(box)
+const plain = await unbox.decrypt(key_wraps.privateKey)
+
+expect(plain).toEqual(key_wrapped.privateKey)
+console.log("ecdh-wraps-ecdh OK")