feat: add log level for better debugging

docs/quickstart/logging.md

@@ -0,0 +1,30 @@
+---
+title: General troubleshooting steps
+layout: default
+parent: Quickstart
+nav_order: 6
+---
+
+
+# Logging
+
+### Set the log level to TRACE
+
+Setting the log level to trace configures the server to trace-log all the headers given in forward auth requests.
+
+This is helpful to confirm that certain required Headers are correctly forwarded from the reverse proxy.
+
+
+
+### When using the environment variable
+
+Set the Goma log level to TRACE:
+
+Add the following block to your .env file:
+```shell
+GOMA_LOG_LEVEL=trace
+```
+
+### When using a configuration file
+
+Edit the Goma settings and set `logLevel: trace`.