fully replicate the commit.sh script as is

In fact, this script is missing some things we might like it to have
(e.g., making sure we're really in the right directory).

.gitignore

@@ -0,0 +1 @@
+__pycache__/

git.py

@@ -0,0 +1,5 @@
+import subprocess
+from typing import Sequence
+
+def exec(*args: Sequence[str]):
+    return subprocess.call(["git", *args])

tzk.py

@@ -1,27 +1,37 @@
 from abc import ABC, abstractmethod, abstractclassmethod
 import argparse
+import os
+
+import git
 
 
 class CliCommand(ABC):
     @abstractclassmethod
-    def setup_arguments(self, parser):
+    def setup_arguments(self, parser: argparse.ArgumentParser) -> None:
         raise NotImplementedError
 
     @abstractmethod
-    def execute(self, parser):
+    def execute(self, parser: argparse.ArgumentParser) -> None:
         raise NotImplementedError
 
 
 class CommitCommand(CliCommand):
     cmd = "commit"
-    help = "Do a commit"
+    help = "Commit all changes to the wiki repository."
 
     @classmethod
-    def setup_arguments(self, parser):
-        pass
+    def setup_arguments(self, parser: argparse.ArgumentParser) -> None:
+        parser.add_argument(
+            "-m, --message",
+            metavar="MSG",
+            help="Commit message to use.",
+            default="daily checkpoint")
 
-    def execute(self, args):
-        print(f"We have committed!")
+    def execute(self, args: argparse.Namespace) -> None:
+        os.chdir("zk-wiki")
+        git.exec("add", "-A")
+        git.exec("commit", "-m", args.message)
+        git.exec("push", "backup")
 
 
 parser = argparse.ArgumentParser()
@@ -32,4 +42,6 @@ for command in CliCommand.__subclasses__():
     command.setup_arguments(subparser)
 
 args = parser.parse_args()
+print(type(args))
+9/0
 args._cls().execute(args)