Add enzyme key to sample configuration

Author: bytesnake

config.example.toml

@@ -135,6 +135,9 @@ changelog-seen = 2
 # Whether or not to specify `-DLLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN=YES`
 #allow-old-toolchain = false
 
+# Whether to build enzyme
+#enzyme = false
+
 # Whether to include the Polly optimizer.
 #polly = false