Add screenshots of examples

When looking into wgpu-rs as a replacement for WebGL I went to the
examples directory on GitHub to browse for a bit.

I wanted to see some of the examples at a glance without needing to
clone the repository.

This commit enables that by adding a README to each example with a
description of the example and screenshots / example output.

In a few cases the description is a bit redundant - but my hope is that
in the future we can improve all the READMEs.

Being a web API and thus very accessible, WebGPU could end up being many
people's first introduction to graphics programming so the lower we make
the barrier the better.

.gitignore

@@ -12,8 +12,9 @@ Cargo.lock
 # Other
 .DS_Store
 
-# VSCode project
+# IDE/Editor configuration files
 .vscode
+.idea
 
 # Output from capture example
 red.png

examples/boids/README.md

@@ -0,0 +1,13 @@
+# boids
+
+Flocking boids example with gpu compute update pass
+
+## To Run
+
+```
+cargo run --example boids
+```
+
+## Screenshots
+
+![Boids example](./screenshot.png)

examples/capture/README.md

@@ -0,0 +1,18 @@
+# capture
+
+This example shows how to capture an image by rendering it to a texture, copying the texture to
+a buffer, and retrieving it from the buffer.
+
+This could be used for "taking a screenshot," with the added benefit that this method doesn't
+require a window to be created.
+
+## To Run
+
+```
+cargo run --example capture
+open examples/capture/red.png
+```
+
+## Screenshots
+
+![Capture example](./screenshot.png)

examples/cube/README.md

@@ -0,0 +1,13 @@
+# cube
+
+This example renders a textured cube.
+
+## To Run
+
+```
+cargo run --example cube
+```
+
+## Screenshots
+
+![Cube example](./screenshot.png)

examples/describe/README.md

@@ -0,0 +1,16 @@
+# describe
+
+This example prints output describing the adapter in use.
+
+## To Run
+
+```
+cargo run --example describe
+```
+
+## Example output
+
+```
+# You might see different output as it depends on your graphics card
+AdapterInfo { name: "Intel(R) UHD Graphics 630", vendor: 0, device: 0, device_type: IntegratedGpu, backend: Metal }
+```

examples/hello-compute/README.md

@@ -0,0 +1,22 @@
+# hello-compute
+
+Runs a compute shader to determine the number of iterations of the rules from
+Collatz Conjecture
+
+- If n is even, n = n/2
+- If n is odd, n = 3n+1
+
+that it will take to finish and reach the number `1`.
+
+## To Run
+
+```
+# Pass in any 4 numbers as arguments
+RUST_LOG=hello_compute cargo run --example hello-compute 1 4 3 295
+```
+
+## Example Output
+
+```
+[2020-04-25T11:15:33Z INFO  hello_compute] Times: [0, 2, 7, 55]
+```

examples/hello-triangle/README.md

@@ -0,0 +1,13 @@
+# hello-triangle
+
+This example renders a triangle to a window.
+
+## To Run
+
+```
+cargo run --example hello-triangle
+```
+
+## Screenshots
+
+![Triangle window](./screenshot.png)

examples/mipmap/README.md

@@ -0,0 +1,13 @@
+# mipmap
+
+This example shows how to generate and make use of mipmaps.
+
+## To Run
+
+```
+cargo run --example mipmap
+```
+
+## Screenshots
+
+![Mip maps](./screenshot.png)

examples/msaa-line/README.md

@@ -0,0 +1,13 @@
+# msaa-line
+
+This example shows how to render lines using MSAA.
+
+## To Run
+
+```
+cargo run --example msaa-line
+```
+
+## Screenshots
+
+![MSAA line](./screenshot.png)

examples/shadow/README.md

@@ -0,0 +1,13 @@
+# shadow
+
+This animated example demonstrates shadow mapping.
+
+## To Run
+
+```
+cargo run --example shadow
+```
+
+## Screenshots
+
+![Shadow mapping](./screenshot.png)

examples/skybox/README.md

@@ -0,0 +1,15 @@
+# skybox
+
+This animated example demonstrates rendering a skybox.
+
+## To Run
+
+```
+cargo run --example skybox
+```
+
+## Screenshots
+
+![Skybox](./screenshot.png)
+
+![Skybox 2](./screenshot2.png)