Incorrect decoding command in developer guide

[juwon8891]

Description:
The developer guide documentation incorrectly states the decoding command. The example for decoding JWT tokens includes an unnecessary "-" in the base64 command. The correct command should omit this extra argument.

For more details, refer to the developer guide.

AS-IS

TOKEN=$(curl https://raw.githubusercontent.com/envoyproxy/gateway/main/examples/kubernetes/jwt/with-different-claim.jwt -s) && echo "$TOKEN" | cut -d '.' -f2 - | base64 --decode -

TO-BE

TOKEN=$(curl https://raw.githubusercontent.com/envoyproxy/gateway/main/examples/kubernetes/jwt/with-different-claim.jwt -s) && echo "$TOKEN" | cut -d '.' -f2 | base64 --decode

[zirain]

cc @zhaohuabing