docs: add readme

Author: lu1as

Diff for: README.md

@@ -0,0 +1,14 @@
+# jwks-federation-server
+
+A simple service which serves a JWKS endpoint containing public keys which are fetched from multiple upstream sources.
+
+## Usage
+
+Create a config file named `config.yaml` based on the sample `config.sample.yaml` file. Next, update `jwks_urls` and optionally limit the keys which gets import from upstream JWKS URLs by defining `allowed_kids`. 
+
+```sh
+# start container
+podman run -d -p 8080:8080 -v $PWD/config.yaml:/config.yaml:ro ghcr.io/nimbolus/jwks-federation-server
+# sample request
+curl localhost:8080/.well-known/jwks.json
+```

Diff for: config.sample.yaml

@@ -3,6 +3,4 @@ update_interval: 1h
 jwks_urls:
   - https://vault.example.com/v1/identity/oidc/.well-known/keys
   - https://keycloak.example.com/realms/master/protocol/openid-connect/certs
-allowed_kids:
-  - 443ec592-bdc2-49dd-abc0-c2faedc6dcda
-  - 63178a29-0382-4180-906a-9d86609645ca
+allowed_kids: []