Update readme, cleanup unused code.

Author: navied

Dockerfile

@@ -1,35 +1,24 @@
 # Secure-Webhook
 
-Securely call CD servers / notification services after your Action finishes
-
-## Credit
-
-Thanks goes to https://github.com/koraykoska/secure-actions-webhook
+Securely call Webhook endpoint after your Action finishes
 
 ## Usage
 
-Sending a string:
+Sending a json string, ``url``, and ``hmacSecret`` are required fields, and ``data`` is optional.
 
 ```yaml
 - name: Webhook
-  uses: navied/secure-actions-webhook@0.1.3
-  env:
-    REQUEST_URI: ${{ secrets.REQUEST_URI }}
-    REQUEST_DATA: "something_interesting"
-    HMAC_SECRET: ${{ secrets.HMAC_SECRET }}
+  uses: navied/secure-actions-webhook@0.2.0
+  with:
+    url: https://example.com
+    data: '{ "example": "data" }'
+    hmacSecret: ${{ secrets.HMAC_SECRET }}
 ```
 
-Sending a json string:
+The request will include the header `X-Hub-Signature`, which is the hmac signature of the raw body just like in Github webhooks, and also the header `X-Hub-SHA` which is the SHA of the commit running the github action.
 
-```yaml
-- name: Webhook
-  uses: navied/secure-actions-webhook@0.1.3
-  env:
-    REQUEST_URI: ${{ secrets.REQUEST_URI }}
-    REQUEST_DATA: '{ "something": "interesting" }'
-    HMAC_SECRET: "secret_used_to_generate_signature"
-```
+Verify it on your endpoint for integrity.
 
-The request will include the header `X-Hub-Signature`, which is the hmac signature of the raw body just like in Github webhooks.
+## Credit
 
-Verify it on your endpoint for integrity.
+Thanks to https://github.com/koraykoska/secure-actions-webhook for providing the base signature generation code.