Update low level docs

Author: easbar

docs/core/low-level-api.md

@@ -39,7 +39,7 @@ But we need to decouple requests from each other and therefor we create a very l
 
 The virtual nodes and edges have a higher `int` ID than `graph.getNodes()` or `allEdges.length()`
 
-A call `queryGraph.lookup(allQRs)` will determine the correct node for all `QueryResult`s: and either 
+A call `QueryGraph.create(graph, allQRs)` will determine the correct node for all `QueryResult`s: and either 
 create new virtual nodes or if close enough use the existing junction node.
 
 ### Create and save the graph
@@ -73,8 +73,7 @@ if (!index.loadExisting())
 ```java
 QueryResult fromQR = index.findClosest(latitudeFrom, longituteFrom, EdgeFilter.ALL_EDGES);
 QueryResult toQR = index.findClosest(latitudeTo, longituteTo, EdgeFilter.ALL_EDGES);
-QueryGraph queryGraph = new QueryGraph(graph);
-queryGraph.lookup(fromQR, toQR);
+QueryGraph queryGraph = QueryGraph.create(graph, fromQR, toQR);
 Path path = new Dijkstra(queryGraph, encoder).calcPath(fromQR.getClosestNode(), toQR.getClosestNode());
 ```
 
@@ -100,7 +99,8 @@ EdgeIteratorState edge = graph.edge(fromId, toId);
 
 // Prepare the graph for fast querying ...
 TraversalMode tMode = TraversalMode.NODE_BASED;
-PrepareContractionHierarchies pch = new PrepareContractionHierarchies(ghStorage, encoder, weighting, tMode);
+CHConfig chConfig = CHConfig.nodeBased("chGraphName", weighting);
+PrepareContractionHierarchies pch = new PrepareContractionHierarchies(ghStorage, chConfig);
 pch.doWork();
 
 // flush after preparation!
@@ -117,8 +117,7 @@ if (!index.loadExisting())
 // calculate path is identical
 QueryResult fromQR = index.findClosest(latitudeFrom, longituteFrom, EdgeFilter.ALL_EDGES);
 QueryResult toQR = index.findClosest(latitudeTo, longituteTo, EdgeFilter.ALL_EDGES);
-QueryGraph queryGraph = new QueryGraph(graph);
-queryGraph.lookup(fromQR, toQR);
+QueryGraph queryGraph = QueryGraph.create(graph, fromQR, toQR);
 
 // create the algorithm using the PrepareContractionHierarchies object
 AlgorithmOptions algoOpts = AlgorithmOptions.start().