Update Documentation for Directed Edges (createEdgeDirected method)

[antonioacampos]

I noticed that the current documentation for the Graphp/GraphViz library shows the use of the method createEdgeDirected to create directed edges from a Graph object, like this:
$graph = new Graphp\Graph\Graph();

$edge = $graph->createEdgeDirected($blue, $red);
However, it seems that the library has been updated, and the method createEdgeDirected no longer exists. Now, edges can be created from vertices using createEdgeTo instead, as shown below:

$transitionVertex = $graph->createVertex($transitionName);
$transitionVertex->createEdgeTo($toPlace);

It would be great to update the documentation to reflect this change, so that developers can follow the current implementation more easily. I am happy to help with this update if needed.

[kulsoom2003]

It seems that changes were made to the API from createEdgeTo to createEdgeDirected in #166, #175, and #178 for a more explicit distinction between directed and undirected edges. Unless I am missing a more recent update, this may be the reason for inconsistency.

Please could you provide a link for any page in the documentation using createEdgeTo, or an inconsistent mention of createEdgeDirected?