Add plugin discovery based on package name prefix

Author: clane9

src/niftyone/__init__.py

@@ -1,5 +1,7 @@
 """Large-scale neuroimaging visualization using FiftyOne."""
 
+# Import all plugins. In particular this should register user's custom generators
+from . import plugins
 from ._version import __version__, __version_tuple__
 
 # Register existing views

src/niftyone/plugins.py

@@ -0,0 +1,13 @@
+"""NiftyOne plugin discovery based on 'niftyone_{plugin_name}' naming convention."""
+
+import importlib
+import pkgutil
+
+PLUGIN_PREFIX = "niftyone_"
+
+# https://packaging.python.org/en/latest/guides/creating-and-discovering-plugins/#using-naming-convention
+PLUGINS = {
+    name: importlib.import_module(name)
+    for finder, name, ispkg in pkgutil.iter_modules()
+    if name.startswith(PLUGIN_PREFIX)
+}