Fix the example/ directory link (#416)

Author: jparise

example/README.md

@@ -1,19 +1,19 @@
 # Example
 
-The [`example/`](ex) directory of elixir-thrift contains an implementation of a simple calculator service. It serves two purposes:
+The [`example/`][ex] directory of elixir-thrift contains an implementation of a simple calculator service. It serves two purposes:
 
 1. How to use this library.
 2. Example of what elixir-thrift generated code looks like.
 
-[ex]: https://github.com/pinterest/elixir-thrift/example
+[ex]: https://github.com/pinterest/elixir-thrift/tree/master/example
 
 ## Calculator Service
 
-The service is very simple, and implements the four basic arithmetic operations: addition, subtraction, multiplication, and division. It demonstrates [how to add a Thrift server to a supervision tree](supervisor), and [how to write a handler](handler) for a [service defined in Thrift](thrift-defs). It also demonstrates how to use exceptions by implementing a division-by-zero exception.
+The service is very simple, and implements the four basic arithmetic operations: addition, subtraction, multiplication, and division. It demonstrates [how to add a Thrift server to a supervision tree][supervisor], and [how to write a handler][handler] for a [service defined in Thrift][thrift-defs]. It also demonstrates how to use exceptions by implementing a division-by-zero exception.
 
-For client usage, you should consult the [test cases](tests) to see how to make requests to a Thrift service.
+For client usage, you should consult the [test cases][tests] to see how to make requests to a Thrift service.
 
-[handler]: https://github.com/pinterest/elixir-thrift/example/lib/calculator/service_handler.ex
-[supervisor]: https://github.com/pinterest/elixir-thrift/example/lib/calculator/application.ex
-[tests]: https://github.com/pinterest/elixir-thrift/example/test/calculator_test.exs
-[thrift-defs]: https://github.com/pinterest/elixir-thrift/example/thrift/calculator.thrift
+[handler]: https://github.com/pinterest/elixir-thrift/tree/master/example/lib/calculator/service_handler.ex
+[supervisor]: https://github.com/pinterest/elixir-thrift/tree/master/example/lib/calculator/application.ex
+[tests]: https://github.com/pinterest/elixir-thrift/tree/master/example/test/calculator_test.exs
+[thrift-defs]: https://github.com/pinterest/elixir-thrift/tree/master/example/thrift/calculator.thrift