spatial_neigbours extensibility features and clarification

docs/api.md

@@ -109,3 +109,18 @@ import squidpy as sq
     datasets.visium_hne_image_crop
     datasets.visium_fluo_image_crop
 ```
+
+
+## Extensibility
+```{eval-rst}
+.. module:: squidpy.gr.neighbors
+.. currentmodule:: squidpy
+.. autosummary::
+    :toctree: api
+
+    gr.neighbors.GraphBuilder
+    gr.neighbors.KNNBuilder
+    gr.neighbors.RadiusBuilder
+    gr.neighbors.DelaunayBuilder
+    gr.neighbors.GridBuilder
+```

src/squidpy/gr/__init__.py

@@ -2,7 +2,12 @@
 
 from __future__ import annotations
 
-from squidpy.gr._build import SpatialNeighborsResult, mask_graph, spatial_neighbors
+from squidpy.gr import neighbors
+from squidpy.gr._build import (
+    SpatialNeighborsResult,
+    mask_graph,
+    spatial_neighbors,
+)
 from squidpy.gr._ligrec import ligrec
 from squidpy.gr._nhood import (
     NhoodEnrichmentResult,
@@ -18,6 +23,7 @@
 __all__ = [
     "SpatialNeighborsResult",
     "NhoodEnrichmentResult",
+    "neighbors",
     "mask_graph",
     "spatial_neighbors",
     "ligrec",