Add placeholder implementation

Add a minimal backend which just calls through to
xarray.open_dataset without adding any functionality.

Author: pont-us

xrenmap/xrenmap.py

@@ -0,0 +1,15 @@
+import os
+from collections.abc import Iterable
+from typing import Any
+
+import xarray as xr
+
+class EnmapEntrypoint(xr.backends.BackendEntrypoint):
+
+    def open_dataset(
+        self,
+        filename_or_obj: str | os.PathLike[Any],
+        *,
+        drop_variables: str | Iterable[str] | None = None,
+    ) -> xr.Dataset:
+        return xr.open_dataset(filename_or_obj)