Fixes https://github.com/bevyengine/bevy/issues/1207
# Objective
Right now, it's impossible to capture a screenshot of the entire window
without forking bevy. This is because
- The swapchain texture never has the COPY_SRC usage
- It can't be accessed without taking ownership of it
- Taking ownership of it breaks *a lot* of stuff
## Solution
- Introduce a dedicated api for taking a screenshot of a given bevy
window, and guarantee this screenshot will always match up with what
gets put on the screen.
---
## Changelog
- Added the `ScreenshotManager` resource with two functions,
`take_screenshot` and `save_screenshot_to_disk`
# Objective
- alternative to #2895
- as mentioned in #2535 the uuid based ids in the render module should be replaced with atomic-counted ones
## Solution
- instead of generating a random UUID for each render resource, this implementation increases an atomic counter
- this might be replaced by the ids of wgpu if they expose them directly in the future
- I have not benchmarked this solution yet, but this should be slightly faster in theory.
- Bevymark does not seem to be affected much by this change, which is to be expected.
- Nothing of our API has changed, other than that the IDs have lost their IMO rather insignificant documentation.
- Maybe the documentation could be added back into the macro, but this would complicate the code.
#3457 adds the `doc_markdown` clippy lint, which checks doc comments to make sure code identifiers are escaped with backticks. This causes a lot of lint errors, so this is one of a number of PR's that will fix those lint errors one crate at a time.
This PR fixes lints in the `bevy_render` crate.
This makes the [New Bevy Renderer](#2535) the default (and only) renderer. The new renderer isn't _quite_ ready for the final release yet, but I want as many people as possible to start testing it so we can identify bugs and address feedback prior to release.
The examples are all ported over and operational with a few exceptions:
* I removed a good portion of the examples in the `shader` folder. We still have some work to do in order to make these examples possible / ergonomic / worthwhile: #3120 and "high level shader material plugins" are the big ones. This is a temporary measure.
* Temporarily removed the multiple_windows example: doing this properly in the new renderer will require the upcoming "render targets" changes. Same goes for the render_to_texture example.
* Removed z_sort_debug: entity visibility sort info is no longer available in app logic. we could do this on the "render app" side, but i dont consider it a priority.
