add Flask

Author: u-hossy

backend/README.md

@@ -1 +1,8 @@
 # バックエンド
+
+## 開発サーバーの起動方法
+
+```bash
+# pwd is at backend/
+poetry run python3 src/project_experiment/hello.py
+```

backend/poetry.lock

@@ -8,6 +8,7 @@ authors = [
 readme = "README.md"
 requires-python = ">=3.12"
 dependencies = [
+    "flask (>=3.1.2,<4.0.0)"
 ]
 
 [tool.poetry]

backend/pyproject.toml

@@ -0,0 +1,12 @@
+from flask import Flask
+
+app = Flask(__name__)
+
+
+@app.route("/")
+def hello_world():
+    return "<p>Hello, World!</p>"
+
+
+if __name__ == "__main__":
+    app.run(host="0.0.0.0", port=5000)