minor: changed formatting

Author: barriesegal

source/faq/storage.txt

@@ -19,10 +19,12 @@ What are memory mapped files?
 -----------------------------
 
 
-A memory-mapped file is a file whose data has been mapped to a region of virtual memory via the mmap() system call. Memory-mapped files play a critical role in the MongoDB storage engine.  By using memory mapped
-files MongoDB can treat the content of its data files as if they were
-in memory. This provides MongoDB with an extremely fast and simple
-method for accessing and manipulating data.
+A memory-mapped file is a file whose data has been mapped to a region of
+virtual memory via the ``mmap()`` system call. Memory-mapped files play a
+critical role in the MongoDB storage engine. By using memory mapped files
+MongoDB can treat the content of its data files as if they were in memory.
+This provides MongoDB with an extremely fast and simple method for accessing
+and manipulating data.
 
 How do memory mapped files work?
 --------------------------------