Add landing page in front of web converter

web/app.py

@@ -45,6 +45,16 @@ def require_auth(credentials: HTTPBasicCredentials = Depends(security)):
 
 
 @app.get("/", response_class=HTMLResponse)
+def landing(request: Request):
+    return templates.TemplateResponse(
+        "landing.html",
+        {
+            "request": request,
+        },
+    )
+
+
+@app.get("/app", response_class=HTMLResponse)
 def index(request: Request, _: None = Depends(require_auth)):
     return templates.TemplateResponse(
         "index.html",