feat: Add package structure for TheChart, implement entry points for console scripts and module execution

pyproject.toml

@@ -15,6 +15,9 @@ dependencies = [
     "ttkthemes>=3.2.2",
 ]
 
+[project.scripts]
+thechart = "thechart.__main__:main"
+
 [dependency-groups]
 dev = [
     "pre-commit>=4.2.0",
@@ -104,3 +107,15 @@ indent-style = "space"       # Use spaces for indentation
 
 [tool.ruff.lint.pycodestyle]
 max-line-length = 88
+
+[build-system]
+requires = ["setuptools>=68", "wheel"]
+build-backend = "setuptools.build_meta"
+
+[tool.setuptools]
+package-dir = { "" = "src" }
+
+[tool.setuptools.packages.find]
+where = ["src"]
+include = ["thechart*"]
+exclude = ["tests*"]