Fix `targets` data type in the doc

docs/beginner/tutorial3-pipeline/README.md

@@ -187,11 +187,11 @@ let render_pipeline = device.create_render_pipeline(&wgpu::RenderPipelineDescrip
     fragment: Some(wgpu::FragmentState { // 3.
         module: &shader,
         entry_point: "fs_main",
-        targets: &[wgpu::ColorTargetState { // 4.
+        targets: &[Some(wgpu::ColorTargetState { // 4.
             format: config.format,
             blend: Some(wgpu::BlendState::REPLACE),
             write_mask: wgpu::ColorWrites::ALL,
-        }],
+        })],
     }),
     // continued ...
 ```

docs/showcase/windowless/README.md

@@ -158,12 +158,12 @@ let render_pipeline = device.create_render_pipeline(&wgpu::RenderPipelineDescrip
     fragment: Some(wgpu::FragmentState {
         module: &fs_module,
         entry_point: "main",
-        targets: &[wgpu::ColorTargetState {
+        targets: &[Some(wgpu::ColorTargetState {
             format: texture_desc.format,
             alpha_blend: wgpu::BlendState::REPLACE,
             color_blend: wgpu::BlendState::REPLACE,
             write_mask: wgpu::ColorWrites::ALL,
-        }],
+        })],
     }),
     primitive: wgpu::PrimitiveState {
         topology: wgpu::PrimitiveTopology::TriangleList,