app,create-app: fix index path redirect

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

.changeset/neat-meals-arrive.md

@@ -0,0 +1,12 @@
+---
+'@backstage/create-app': patch
+---
+
+Updated the index page redirect to work with apps served on a different base path than `/`.
+
+To apply this change to an existing app, remove the `/` prefix from the target route in the `Navigate` element in `packages/app/src/App.tsx`:
+
+```diff
+-<Navigate key="/" to="/catalog" />
++<Navigate key="/" to="catalog" />
+```

docs/features/software-catalog/catalog-customization.md

@@ -187,7 +187,7 @@ new `CustomCatalogIndexPage`.
 # packages/app/src/App.tsx
 const routes = (
   <FlatRoutes>
-    <Navigate key="/" to="/catalog" />
+    <Navigate key="/" to="catalog" />
 -    <Route path="/catalog" element={<CatalogIndexPage />} />
 +    <Route path="/catalog" element={<CustomCatalogIndexPage />} />
 ```

packages/app/src/App.tsx

@@ -98,7 +98,7 @@ const AppRouter = app.getRouter();
 
 const routes = (
   <FlatRoutes>
-    <Navigate key="/" to="/catalog" />
+    <Navigate key="/" to="catalog" />
     <Route path="/catalog" element={<CatalogIndexPage />} />
     <Route
       path="/catalog/:namespace/:kind/:name"

packages/create-app/templates/default-app/packages/app/src/App.tsx

@@ -42,7 +42,7 @@ const AppRouter = app.getRouter();
 
 const routes = (
   <FlatRoutes>
-    <Navigate key="/" to="/catalog" />
+    <Navigate key="/" to="catalog" />
     <Route path="/catalog" element={<CatalogIndexPage />} />
     <Route
       path="/catalog/:namespace/:kind/:name"