Update README

Author: Skn0tt

README.md

@@ -7,12 +7,12 @@ Useful for securing webhooks.
 On the webhook sender:
 
 ```ts
-import { sign } from "secure-webhooks"
+import { symmetric } from "secure-webhooks"
 
 const secret = "some shared secret"
 const payload = "...";
 
-const signature = sign(payload, secret);
+const signature = symmetric.sign(payload, secret);
 
 sendToWebhookReceiver({
   body: payload,
@@ -26,12 +26,12 @@ sendToWebhookReceiver({
 On the webhook receiver:
 
 ```ts
-import { verify } from "secure-webhooks"
+import { symmetric } from "secure-webhooks"
 
 const secret = "some shared secret" // the same as above
 
 app.post("/webhook-endpoint", (req, res) => {
-  const isTrustWorthy = verify(
+  const isTrustWorthy = symmetric.verify(
     req.body, // 👈 needs to be exactly the same as above, make sure to disable any body parsing for this route
     secret,
     req.headers["x-webhook-signature"]
@@ -44,4 +44,10 @@ app.post("/webhook-endpoint", (req, res) => {
 
   ...
 })
-```
+```
+
+Same works with asymmetric mode:
+
+```ts
+import { asymmetric } from "secure-webhooks"
+```