Added documentation about multi-threaded use

Author: oschwald

CHANGELOG.md

@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+0.3.2 (201X-XX-XX)
+------------------
+
+* Added tests and documentation for mutli-threaded use.
+
 0.3.1 (2013-11-05)
 ------------------
 

README.md

@@ -42,6 +42,10 @@ as they provide a convenient representation of multi-type data structures and
 the databind package of Jackson 2 supplies many tools for interacting with the
 data in this format.
 
+We recommend reusing the `Reader` object rather than creating a new one for
+each lookup. The creation of this object is relatively expensive as it must
+read in metadata for the file.
+
 ## Example ##
 
 ```java
@@ -59,6 +63,12 @@ reader.close();
 
 ```
 
+## Multi-Threaded Use ##
+
+This API fully supports use in multi-threaded applications. In such
+applications, we suggest creating one `Reader` object and sharing that among
+threads.
+
 ## Format ##
 
 The MaxMind DB format is an open format for quickly mapping IP addresses to