Improve README and convert to markdown.

README → README.md

-This is the root directory of the "NoFib Haskell benchmark suite".  It
+# NoFib: Haskell Benchmark Suite
+
+This is the root directory of the "NoFib Haskell benchmark suite". It
 should be part of a GHC source tree, that is the 'nofib' directory
 should be at the same level in the tree as 'compiler' and 'libraries'.
 
-To run the tests:
+## Package Depedencies
+
+Please make sure you have the following packages installed for your
+system GHC:
+ * html
+ * regex-compat (will install: mtl, regex-base, regex-posix)
+
+## Using
+
+Then, to run the tests, execute:
 
   $ make clean
   $ make boot
   $ make 2>&1 | tee nofib-log
 
-will put the results in the file 'nofib-log'. You can pass extra options to a
-nofib run using the EXTRA_HC_OPTS variable like this:
+This will put the results in the file 'nofib-log'. You can pass extra
+options to a nofib run using the EXTRA_HC_OPTS variable like this:
 
   $ make clean
   $ make boot
   $ make EXTRA_HC_OPTS="-fllvm" >&1 | tee nofib-llvm-log
 
 To compare the results of multiple runs, use the program in
-../utils/nofib-analyse.  Something like this:
+../utils/nofib-analyse, for example:
 
   $ nofib-analyse nofib-log-6.4.2 nofib-log-6.6
 
 to generate a comparison of the runs in captured in 'nofib-log-6.4.2'
-and 'nofib-log-6.6'.  When making comparisons, be careful to ensure
+and 'nofib-log-6.6'. When making comparisons, be careful to ensure
 that the things that changed between the builds are only the things
-that you *wanted* to change.  There are lots of variables: machine,
+that you _wanted_ to change. There are lots of variables: machine,
 GHC version, GCC version, C libraries, static vs. dynamic GMP library,
-build options, run options, and probably lots more.  To be on the safe
+build options, run options, and probably lots more. To be on the safe
 side, make both runs on the same unloaded machine.
 
+## Configuration
+
+There are some options you might want to tweak; search for nofib in
+../mk/config.mk, and override settings in ../mk/build.mk as usual.
+
+## Extra Metrics: Valgrind
+
 To get instruction counts, memory reads/writes, and "cache misses",
 you'll need to get hold of Cachegrind, which is part of Valgrind
 (http://valgrind.org).
 
-There are some options you might want to tweak; search for nofib in
-../mk/config.mk, and override settings in ../mk/build.mk as usual.
+## Extra Packages
 
-Package Requirements:
- * html
- * regex-compat (mtl, regex-base, regex-posix)
- * stm (for smp benches)
+Some benchmarks aren't run by default and require extra packages are
+installed for the GHC compiler being tested. These packages include:
+ * stm - for smp benchmarks