Added Markdown to HACKING file

HACKING.md

@@ -15,15 +15,19 @@ Here are some directions to get you started:
      Helper script to get some uniformity in the style:
      $ make style
 
-     If you use vim see the "Vim: How to prevent trailing whitespaces"
-     http://www.carbon-project.org/Vim__How_to_prevent_trailing_whitespaces.html
+     If you use vim see the [Vim: How to prevent trailing whitespaces](http://www.carbon-project.org/Vim__How_to_prevent_trailing_whitespaces.html).
 
   2. Chase warnings: no warning should be introduced by your changes
   Depending what you touch, you can check with:
+
     2.1 When using autotools
+
             $ autoreconf -Wall -vis
+
     2.2 When compiling
+
       2.2.1 Using extra flags:
+
             $ export CFLAGS="-Wall -g -O2 -Wextra -pipe -funsigned-char -fstrict-aliasing \
               -Wchar-subscripts -Wundef -Wshadow -Wcast-align -Wwrite-strings -Wunused \
               -Wuninitialized -Wpointer-arith -Wredundant-decls -Winline -Wformat \
@@ -33,23 +37,32 @@ Here are some directions to get you started:
          $ ./configure
          $ make clean
          $ make
+
       2.2.2 Using clang:
-        You can use same CFLAGS but also "-Wunreachable-code"
+
+        You can use same CFLAGS but also `-Wunreachable-code`
+
             $ scan-build ./configure
          $ make clean
          $ scan-build make
-      2.2.3 Using cppcheck (v1.58 or higher):
+
+      2.2.3 Using `cppcheck` (v1.58 or higher):
+
           $ make cppcheck
+
     2.3 When Debianizing
+
          $ lintian --info --display-info --display-experimental *deb
         or (shorter version)
          $ lintian -iIE *deb
 
   3. Preserve cross-platform compatility
+
      The source code should remain compilable across various platforms,
      including some you probably cannot test alone so keep it in mind.
      Supported platforms:
+
      - Linux
      - FreeBSD
      - Mac OS X
-     - Windows with Mingw
+     - Windows with MinGW