fix(cli): check whether project directory exists and is a directory

src/jcloud_docsgen/cli.py

@@ -24,10 +24,12 @@ import argparse
 import pathlib
 
 def existing_directory(path: str) -> pathlib.Path:
-    try:
-        return pathlib.Path(path)
-    except (FileNotFoundError, NotADirectoryError) as e:
-        raise argparse.ArgumentTypeError(f'{e.filename}{": " + e.args[1] if len(e.args) > 1 else ""}')
+    _path = path
+    path = pathlib.Path(_path)
+    if not path.exists():
+        raise argparse.ArgumentTypeError(f'{_path}: no such file or directory')
+    if not path.is_dir():
+        raise argparse.ArgumentTypeError(f'{_path}: not a directory')
 
 def main() -> int:
     argument_parser = argparse.ArgumentParser()