typo - missing are

docs/beginner/tutorial2-swapchain/README.md

@@ -91,7 +91,7 @@ As of writing, the wgpu implementation doesn't allow you to customize much of re
         };
         let swap_chain = device.create_swap_chain(&surface, &sc_desc);
 ```
-Here we defining and creating the `swap_chain`. The `usage` field describes how the `swap_chain`'s underlying textures will be used. `OUTPUT_ATTACHMENT` specifies that the textures will be used to write to the screen (we'll talk about more `TextureUsage`s later).
+Here we are defining and creating the `swap_chain`. The `usage` field describes how the `swap_chain`'s underlying textures will be used. `OUTPUT_ATTACHMENT` specifies that the textures will be used to write to the screen (we'll talk about more `TextureUsage`s later).
 
 The `format` defines how the `swap_chain`s textures will be stored on the gpu. Usually you want to specify the format of the display you're using. As of writing, I was unable to find a way to query what format the display has through `wgpu`, though [there are plans on including such a method](https://github.com/gfx-rs/wgpu-rs/issues/123#issuecomment-555803321), so `wgpu::TextureFormat::Bgra8UnormSrgb` will do for now. We use `wgpu::TextureFormat::Bgra8UnormSrgb` because that's the format that's [guaranteed to be natively supported by the swapchains of all the APIs/platforms](https://github.com/gfx-rs/wgpu-rs/issues/123#issuecomment-555800583) which are currently supported.
 
@@ -351,4 +351,4 @@ In the event loop we're currently using `*control_flow = ControlFlow::Wait` in m
 
 Modify the `input()` method to capture mouse events, and update the clear color using that. *Hint: you'll probably need to use `WindowEvent::CursorMoved`*
 
-<AutoGithubLink/>
+<AutoGithubLink/>