style: limit line length to 79 characters

Limited the lengths of all lines to 79 characters (if possible).
Additionally, some other lines were breaked for consistence.

src/jcloud_docsgen/cli/cli.py

@@ -35,7 +35,9 @@ def existing_directory(path: str) -> pathlib.Path:
     _path = path
     path = pathlib.Path(_path)
     if not path.exists():
-        raise argparse.ArgumentTypeError(f'{_path}: no such file or directory')
+        raise argparse.ArgumentTypeError(
+            f'{_path}: no such file or directory'
+        )
     if not path.is_dir():
         raise argparse.ArgumentTypeError(f'{_path}: not a directory')
     return path
@@ -79,7 +81,10 @@ def create_argument_parser() -> argparse.ArgumentParser:
 
     argument_parser = argparse.ArgumentParser()
 
-    subparsers = argument_parser.add_subparsers(dest = 'language', required = True)
+    subparsers = argument_parser.add_subparsers(
+        dest = 'language',
+        required = True
+    )
 
     python_parser = subparsers.add_parser(
         _LANG_PYTHON,
@@ -99,19 +104,29 @@ def create_argument_parser() -> argparse.ArgumentParser:
         nargs = '+',
         default = [],
         choices = VALID_PYTHON_SECTIONS,
-        help = 'the sections to be excluded in the documentation. If a section shall be included AND excluded, it is excluded.'
+        help = (
+            'the sections to be excluded in the documentation. '
+            'If a section shall be included AND excluded, it is excluded.'
+        )
     )
     python_parser.add_argument(
         '-H',
         '--allow-html',
         action = 'store_true',
-        help = 'indicates whether HTML is allowed in the documentation. By default, HTML is disabled.'
+        help = (
+            'indicates whether HTML is allowed in the documentation. '
+            'By default, HTML is disabled.'
+        )
     )
     python_parser.add_argument(
         '-T',
         '--allow-tables',
         action = 'store_true',
-        help = 'indicates whether Markdown tables are allowed in the documentation. By default, Markdown tables are disabled. Warning: Markdown tables are not CommonMark.'
+        help = (
+            'indicates whether Markdown tables are allowed in the '
+            'documentation. By default, Markdown tables are disabled. '
+            'Warning: Markdown tables are not CommonMark.'
+        )
     )
 
     return argument_parser