Add an environment.yml file

This provides a convenient way to set up an environment with a
compatible Python version and gdal, which can't be installed
with pip.

Author: pont-us

environment.yml

@@ -0,0 +1,8 @@
+name: efast
+channels:
+  - conda-forge
+dependencies:
+  - python >=3.10,<3.12
+  - gdal
+# Remaining dependencies are listed in pyproject.toml
+# and can be installed with pip.