Add usage example

README.md

@@ -1,3 +1,37 @@
 # pasch
 
 Python-based Arch System Config Helper
+
+```py
+from argparse import ArgumentParser
+
+from pasch import Orchestrator
+from pasch.file import GitFile
+from pasch.modules import Files, Pacman
+
+
+def cfg_git(files: Files, pacman: Pacman) -> None:
+    pacman.install("git")
+    pacman.install("lazygit")
+
+    git_config = GitFile()
+    git_config.set("user", "name", "foo")
+    git_config.set("user", "email", "foo@example.com")
+    git_config.set("pull", "rebase", True)
+    git_config.set("fetch", "prune", True)
+    git_config.set("merge", "conflictstyle", "diff3")
+    files.add(".config/git/config", git_config)
+
+
+parser = ArgumentParser()
+parser.add_argument("-d", "--dry-run", action="store_true")
+args = parser.parse_args()
+
+o = Orchestrator(dry_run=args.dry_run)
+
+files = Files(o)
+pacman = Pacman(o)
+cfg_git(files, pacman)
+
+o.realize()
+```