extend config.toml doc

Author: RalfJung

src/bootstrap/config.toml.example

@@ -203,7 +203,7 @@
 #codegen-units = 1
 
 # Whether or not debug assertions are enabled for the compiler and standard
-# library
+# library. Also enables compilation of debug! and trace! logging macros.
 #debug-assertions = false
 
 # Whether or not debuginfo is emitted