Updated Fuzzing your nim code to rabbit out all the hard bugs (markdown)

Fuzzing-your-nim-code-to-rabbit-out-all-the-hard-bugs.md

@@ -48,7 +48,9 @@ This is a pretty contrived thing, but just imagine this being somewhere in a fil
 
 Save that example in a file called "afl.nim".  Because afl needs to instrument the generated binary code, you need to tell nim to use the compiler frontend afl comes with, instead of whatever your distro defaults to.  Create a file called "afl.nim.cfg" in the same directory and put this in:
 
-```
+```ini
+# nim.cfg for afl-clang
+-d:noSignalHandler
 cc = clang
 clang.exe = "afl-clang"
 clang.linkerexe = "afl-clang"
@@ -59,6 +61,16 @@ This is a working example for OSX, where afl was installed via homebrew. To make
 
 Very important: `-d:noSignalHandler`, because AFL installs it's own signal handler inside instrumented code.
 
+```ini
+# nim.cfg for afl-gcc
+-d:noSignalHandler
+cc = gcc
+gcc.exe = "afl-gcc"
+gcc.linkerexe = "afl-gcc"
+```
+
+This is a working example for Linux. AFL was installed globally with 'apt-get install afl'
+
 ```
 $ nim c -d:noSignalHandler afl
 ```
@@ -113,4 +125,5 @@ trace = 0x10f913050"Traceback (most recent call last)\10"
 
 You can limit the exceptions that are considered crashes by adjusting the except: clause in the example.
 
-Then I'd strongly suggest to start reading up on afl if you want to employ it with confidence.
+Then I'd strongly suggest to start reading up on afl if you want to employ it with confidence.
+