Add FastAPI framework with basics section

snippets/python/[fastapi]/basics/hello-world.md

@@ -0,0 +1,21 @@
+---
+title: Hello, World!
+description: Returns Hello, World! when it recives a GET request made to the root endpoint.
+author: ACR1209
+tags: printing,hello-world,web,api
+---
+
+```py
+from typing import Union
+from fastapi import FastAPI
+
+app = FastAPI()
+
+
+@app.get("/")
+def read_root():
+    return {"msg": "Hello, World!"}
+
+# Usage: 
+# -> Go to http://127.0.0.1:8000/ and you'll see {"msg", "Hello, World!"}
+```