Reformat the beginning of the testing doc to make clear how to run all the tests.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@371001 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/TestingLibcxx.rst b/docs/TestingLibcxx.rst
index d8060fe..eaba214 100644
--- a/docs/TestingLibcxx.rst
+++ b/docs/TestingLibcxx.rst
@@ -8,11 +8,14 @@
 Getting Started
 ===============
 
-libc++ uses LIT to configure and run its tests. The primary way to run the
-libc++ tests is by using make check-libcxx. However since libc++ can be used
-in any number of possible configurations it is important to customize the way
-LIT builds and runs the tests. This guide provides information on how to use
-LIT directly to test libc++.
+libc++ uses LIT to configure and run its tests. 
+
+The primary way to run the libc++ tests is by using `make check-libcxx`. 
+
+However since libc++ can be used in any number of possible
+configurations it is important to customize the way LIT builds and runs
+the tests. This guide provides information on how to use LIT directly to
+test libc++.
 
 Please see the `Lit Command Guide`_ for more information about LIT.