Fix link to PPrint (#87)

* Fix link to PPrint

* Update link to com-lihaoyi organization

Co-authored-by: Lorenzo Gabriele <[email protected]>

Author: steinybot

README.md

@@ -464,7 +464,7 @@ various `debug` call-sites you left lying around and manually tweaking the
 verbosity of each one. Furthermore, if you want additional information like
 `sourcecode.Line` or `sourcecode.File`, that's all just one implicit away.
 
-The [PPrint](http://www.lihaoyi.com/upickle-pprint/pprint)
+The [PPrint](https://github.com/com-lihaoyi/PPrint) 
 library provides a `pprint.log` method that does exactly this: prints out the
 value provided (in this case pretty-printing it with colors and nice formatting
 & indentation) together with the enclosing context and line number, so you