Improvements in packaging.

The ziffers.lark file is not included in the installed package. This was
preventing users from importing the ziffers package from elsewhere.

pyproject.toml

@@ -28,6 +28,21 @@ documentation = "https://github.com/Bubobubobubobubo/ziffers-python"
 repository = "https://github.com/Bubobubobubobubo/ziffers-python"
 
 [tool.black]
-line-length = 88
-target_version = ['py310']
+target_version = ['py311']
 include = '\.pyi?$'
+exclude = '''
+(
+  /(
+      \.eggs         # exclude a few common directories in the
+    | \.git          # root of the project
+    | \.hg
+    | \.mypy_cache
+    | \.tox
+    | \.venv
+    | _build
+    | buck-out
+    | build
+    | dist
+  )/
+)
+'''