README doc tweaks

Author: cliffg-softwarelibre

README.md

@@ -26,7 +26,7 @@ The generated Doxygen documentation for `periodic_timer` is [here](https://conne
 
 ## Library Dependencies
 
-The `periodic_timer` header file has the stand-alone Asio library for a dependency. Specific version (or branch) specs for the Asio dependency is in `cmake/download_asio_cpm.cmake`.
+The `periodic_timer` header file has the stand-alone Asio library for a dependency. Specific version (or branch) specs for the Asio dependency is in [`cmake/download_asio_cpm.cmake`](cmake/download_asio_cpm.cmake).
 
 ## C++ Standard