Add SlicerVolBrain extension

Author: niyaziacer

volbrain.json

@@ -0,0 +1,7 @@
+{
+  "$schema": "https://raw.githubusercontent.com/Slicer/Slicer/main/Schemas/slicer-extension-catalog-entry-schema-v1.0.1.json#",
+  "category": "Quantification",
+  "scm_url": "https://github.com/niyaziacer/SlicerVolBrain.git",
+  "scm_revision": "b4156f73b4ec0a0722778535ed353fce49cccd46",
+  "scm_type": "git"
+}