Move UI example to testbed (#16241)

# Objective

UI example is quite extensive, probably not the best teaching example
anymore.

Closes #16230.

.github/workflows/validation-jobs.yml

@@ -244,7 +244,7 @@ jobs:
 
       - name: First Wasm build
         run: |
-          cargo build --release --example ui --target wasm32-unknown-unknown
+          cargo build --release --example testbed_ui --target wasm32-unknown-unknown
 
       - name: Run examples
         shell: bash

Cargo.toml

@@ -3136,17 +3136,6 @@ description = "Demonstrates how to control the relative depth (z-position) of UI
 category = "UI (User Interface)"
 wasm = true
 
-[[example]]
-name = "ui"
-path = "examples/ui/ui.rs"
-doc-scrape-examples = true
-
-[package.metadata.example.ui]
-name = "UI"
-description = "Illustrates various features of Bevy UI"
-category = "UI (User Interface)"
-wasm = true
-
 [[example]]
 name = "ui_scaling"
 path = "examples/ui/ui_scaling.rs"
@@ -3857,6 +3846,13 @@ doc-scrape-examples = true
 [package.metadata.example.testbed_3d]
 hidden = true
 
+[[example]]
+name = "testbed_ui"
+path = "examples/testbed/ui.rs"
+doc-scrape-examples = true
+
+[package.metadata.example.testbed_ui]
+hidden = true
 
 [[example]]
 name = "testbed_ui_layout_rounding"

examples/README.md

@@ -516,7 +516,6 @@ Example | Description
 [Text Debug](../examples/ui/text_debug.rs) | An example for debugging text layout
 [Text Wrap Debug](../examples/ui/text_wrap_debug.rs) | Demonstrates text wrapping
 [Transparency UI](../examples/ui/transparency_ui.rs) | Demonstrates transparency for UI
-[UI](../examples/ui/ui.rs) | Illustrates various features of Bevy UI
 [UI Material](../examples/ui/ui_material.rs) | Demonstrates creating and using custom Ui materials
 [UI Scaling](../examples/ui/ui_scaling.rs) | Illustrates how to scale the UI
 [UI Texture Atlas](../examples/ui/ui_texture_atlas.rs) | Illustrates how to use TextureAtlases in UI