bootboot: document the protocol and it's configuration options
diff --git a/CONFIG.md b/CONFIG.md
index c1fe14ad..31a2d30c 100644
--- a/CONFIG.md
+++ b/CONFIG.md
@@ -99,6 +99,14 @@ Some keys take *URIs* as values; these are described in the next section.
Note that one can define this last variable multiple times to specify multiple
modules.
* `RESOLUTION` - The resolution to be used. This setting takes the form of `<width>x<height>x<bpp>`. If the resolution is not available, Limine will pick another one automatically. Omitting `<bpp>` will default to 32.
+* Bootboot protocol:
+ * `KERNEL_PATH` - The URI path of the kernel.
+ * `RAMDISK` - The URI path to the ramdisk/initrd.
+ * `BOOTBOOT_ENV` - A configuration key to be passed into the kernel.
+
+ Note that one can define this last variable multiple times to specify multiple
+ environemnt keys.
+ * `RESOLUTION` - The resolution to be used. This setting takes the form of `<width>x<height>x<bpp>`. If the resolution is not available, Limine will pick another one automatically. Omitting `<bpp>` will default to 32.
* stivale and stivale2 protocols:
* `KERNEL_PATH` - The URI path of the kernel.
* `MODULE_PATH` - The URI path to a module.
