Change function name from uv3d to main

The function name "uv3d" triggered ImportError: cannot import name 'main' from 'bdschism.uv3d' when the function uv3d was called in command line.

Author: HansKimDWR

bdschism/bdschism/uv3d.py

@@ -74,7 +74,7 @@
     type=bool,
     help="If true, the file will be moved to run_dir. Otherwise, it will be done in place in outputs.",
 )
-def uv3d(
+def main(
     param_nml,
     bg_dir,
     bg_output_dir,
@@ -204,4 +204,4 @@ def uv3d(
 
 
 if __name__ == "__main__":
-    uv3d()
+    main()