This uses KDL properties, i.e. "host=<hostname>" and can be applied to
any config type. An example is includes in examples/config.kdl.
```kdl
wallpaper_image_path "~/Pictures/desktop.png" host="desktop"
wallpaper_image_path "~/Pictures/laptop.png" host="laptop"
```
Right now, the support is still incomplete (no way to set config) but
we get the devices and set them up and handle current/support events
for the river_libinput_device_v1 devices.
Added pixman and zigimg dependencies
Set up in build.zig, added to both exe and exe_check
Add new protocols:
river-layer-shell-v1
wlr-layer-shell-unstable-v1
xdg-shell (dep of wlr-layer-shell-unstable-v1)
Update Context.zig to hold wl_output, wl_shm, and a WallpaperImage
Also re-ordered all of its fields into alphabetical order
Context.create() now takes a Context.Options struct so that it takes
one arg instead of many smaller args.
Added new WallpaperImage.zig, but it's not yet actually used
Keybinds go in a "keybinds" block and follow the format
<command> <modifiers> <keysym> <options>
But there's also a special "tag_bind" command that just takes modifiers
and one of set_output_tags, set_window_tags, toggle_output_tags, and
toggle_window_tags. It will automatically be used to loop through the
1-9 keys on tags 1<<0 to 1<<9, however, you can still implement those
commands individually if you want.
Config goes in $XDG_CONFIG_HOME/beansprout/config.kdl or
$HOME/.config/beansprout/config.kdl
Config is in the kdl format. Right now, the supported options are
```zig
/// Width of window borders in pixels
border_width: u8 = 2,
/// Color of focused window's border in 0xRRGGBBAA or 0xRRGGBB form
border_color_focused: RiverColor = utils.parseRgbaComptime("0x89b4fa"),
/// Color of uffocused windows' borders in 0xRRGGBBAA or 0xRRGGBB form
border_color_unfocused: RiverColor = utils.parseRgbaComptime("0x1e1e2e"),
/// Where a new window should attach, top or bottom of the stack
attach_mode: AttachMode = .top,
/// Should focus change when the cursor moves onto a new window
focus_follows_pointer: bool = true,
/// Should the pointer warp to the center of newly-focused windows
pointer_warp_on_focus_change: bool = true,
```
I plan to add Keybinds shortly. If parsing the configuration fails,
the default config will be used and the WM will continue loading.
