Merge pull request #101 from AlecGoncharow/master

Update `vulkan` feature to `vulkan-portability` and fix small typo in swapchain

docs/beginner/tutorial1-window/README.md

@@ -30,7 +30,7 @@ To enable the Vulkan backend, add this new section to `Cargo.toml`, and do not f
 ``` toml
 [dependencies.wgpu]
 version = "0.6"
-features = ["vulkan"]
+features = ["vulkan-portability"]
 ```
 
 - This may not be necessary because normally `wgpu-rs` validation will catch problems. In fact that is one of it's

docs/beginner/tutorial2-swapchain/README.md

@@ -375,7 +375,7 @@ The `ops` field takes a `wpgu::Operations` object. This tells wgpu what to do wi
 
 <div class="note">
 
-It's not uncommon to not clear the screen if the streen is going to be completely covered up with objects. If you're scene doesn't cover the entire screen however you'll end up with something like this.
+It's not uncommon to not clear the screen if the screen is going to be completely covered up with objects. If you're scene doesn't cover the entire screen however you'll end up with something like this.
 
 ![./no-clear.png](./no-clear.png)