Rename folder hello_app to match tutorial

.vscode/launch.json

@@ -64,7 +64,7 @@
             "request": "launch",
             "module": "flask",
             "env": {
-                "FLASK_APP": "hello_flask/app.py"                
+                "FLASK_APP": "hello_app/app.py"                
             },
             "args": [
                 "run",

hello_app/__init__.py

@@ -1,2 +1,2 @@
 from flask import Flask
-app = Flask(__name__)
+app = Flask(__name__)

hello_app/app.py

@@ -1,5 +1,5 @@
-from hello_flask import app
-from hello_flask import views
+from hello_app import app
+from hello_app import views
 
 # Time-saver: output a URL to the VS Code terminal so you can easily Ctrl+click to open a browser
 # print('http://127.0.0.1:5000/hello/VSCode')

hello_app/views.py

@@ -1,6 +1,6 @@
 from datetime import datetime
 from flask import Flask, render_template
-from hello_flask import app
+from hello_app import app
 
 @app.route('/')
 def home():