add comments

backend/app.py

backend/config.py

backend/models_shared.py

backend/parse_data.py

backend/routes_auth.py

backend/routes_default.py

frontend/src/Components/Navbar/Navbar.js

frontend/src/Components/Search/MultiLevelOptions.jsx

frontend/src/Components/Search/SearchComponent.jsx

frontend/src/Context/GlobalContext.js

frontend/src/Pages/Dashboard/Barchart.jsx

frontend/src/Pages/Dashboard/Dashboard.jsx

frontend/src/Pages/Dashboard/Map.jsx

frontend/src/Pages/Dashboard/Visualiser.jsx

frontend/src/Pages/SignupSigninForms/SignInForm.jsx

frontend/src/Pages/SignupSigninForms/SignUpForm.jsx

frontend/src/index.js