Add docs for triangle count node label filtering

Author: adamnsch

doc/configs/algorithms-conf.json

@@ -681,6 +681,27 @@
           "default": "2^63^ - 1",
           "optional": true,
           "description": "If a node has a degree higher than this it will not be considered by the algorithm. The triangle count for these nodes will be `-1`."
+        },
+        {
+          "name": "aLabel",
+          "type": "String",
+          "default": "null",
+          "optional": true,
+          "description": "The required node label of the first node in the triangle. If not specified, the algorithm will not filter by label."
+        },
+        {
+          "name": "bLabel",
+          "type": "String",
+          "default": "null",
+          "optional": true,
+          "description": "The required node label of the second node in the triangle. If not specified, the algorithm will not filter by label."
+        },
+        {
+          "name": "cLabel",
+          "type": "String",
+          "default": "null",
+          "optional": true,
+          "description": "The required node label of the third node in the triangle. If not specified, the algorithm will not filter by label."
         }
       ],
       "page_path": "algorithms/triangle-count/"

doc/modules/ROOT/pages/algorithms/triangle-count.adoc

@@ -28,6 +28,15 @@ For more information on this algorithm, see:
 This is described in http://chato.cl/papers/becchetti_2007_approximate_count_triangles.pdf["Efficient Semi-streaming Algorithms for Local Triangle Counting in Massive Graphs"].
 
 
+== Node label filtering
+
+For some use-cases it is useful to only count triangles that contain nodes with specific labels.
+This is also something that can save computation time, as the algorithm will not have to consider nodes that do not match the specified labels.
+
+The algorithm supports node label filtering by allowing you to specify labels for each of the three nodes in the triangle, using the `aLabel`, `bLabel`, and `cLabel` configuration parameters.
+They are optional and can be used individually or in combination.
+
+
 [[algorithms-triangle-count-syntax]]
 == Syntax
 

doc/modules/ROOT/partials/algorithms/triangle-count/specific-configuration.adoc

@@ -1,2 +1,5 @@
 // DO NOT EDIT: File generated automatically by the process_conf.py script
 | maxDegree | Integer | 2^63^ - 1 | yes | If a node has a degree higher than this it will not be considered by the algorithm. The triangle count for these nodes will be `-1`.
+| aLabel | String | null | yes | The required node label of the first node in the triangle. If not specified, the algorithm will not filter by label.
+| bLabel | String | null | yes | The required node label of the second node in the triangle. If not specified, the algorithm will not filter by label.
+| cLabel | String | null | yes | The required node label of the third node in the triangle. If not specified, the algorithm will not filter by label.