Add a helper for loading properties file

config/src/main/groovy/net/neoforged/camelot/config/CamelotConfig.groovy

@@ -5,6 +5,9 @@ import groovy.transform.stc.ClosureParams
 import groovy.transform.stc.FromString
 import net.neoforged.camelot.config.module.ModuleConfiguration
 
+import java.nio.file.Files
+import java.nio.file.Path
+
 /**
  * The class holding Camelot's configuration, that is represented in a Groovy DSL.
  */
@@ -89,4 +92,19 @@ class CamelotConfig {
         }
         return value
     }
+
+    /**
+     * Load a properties file from the given {@code path}.
+     * @param path the path of the properties file
+     * @return the loaded properties
+     */
+    static Properties loadProperties(String path) {
+        final props = new Properties()
+        try (final reader = Files.newBufferedReader(Path.of(path))) {
+            props.load(reader)
+        } catch (Exception ex) {
+            throw new RuntimeException("Failed to read properties file at $path", ex)
+        }
+        return props
+    }
 }

config/src/sample/groovy/sample.camelot.groovy

@@ -1,6 +1,8 @@
 import net.neoforged.camelot.config.module.*
 
 camelot {
+    final secrets = loadProperties('secrets.properties')
+
     token = secret(env('BOT_TOKEN'))
     prefix = '!'
 
@@ -23,7 +25,7 @@ camelot {
     }
 
     module(FilePreview) {
-        auth = patAuthentication(secret(env('GIST_PAT')))
+        auth = patAuthentication(secret(secrets.GIST_PAT))
     }
 
     module(WebServer) {