added fastapi to requirements. First step to replace flask with fastapi

main.py

@@ -0,0 +1,14 @@
+from fastapi import FastAPI
+
+app = FastAPI()
+
+
+@app.get("/")
+def read_root():
+    return {"Hello": "World"}
+
+
+@app.get("/items/{item_id}")
+def read_item(item_id: int, q: str | None = None):
+    return {"item_id": item_id, "q": q}
+