Docs: @Cancellable.

src/main/java/com/llamalad7/mixinextras/sugar/Cancellable.java

@@ -1,10 +1,30 @@
 package com.llamalad7.mixinextras.sugar;
 
+import com.llamalad7.mixinextras.injector.wrapoperation.WrapOperation;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.ModifyConstant;
+import org.spongepowered.asm.mixin.injection.Redirect;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
+/**
+ * Allows you to receive a cancellable {@link CallbackInfo} or {@link CallbackInfoReturnable} as appropriate
+ * from any kind of injector. This allows you to optionally cancel the target method without being forced to use
+ * {@link Inject @Inject}.
+ * <p>
+ * The same {@link CallbackInfo}s will be passed to every handler method in a chain of
+ * {@link WrapOperation @WrapOperation}s (i.e. any number of {@link WrapOperation @WrapOperation}s and at most one inner
+ * {@link Redirect @Redirect} / {@link ModifyConstant @ModifyConstant}). This means you can choose to use the
+ * {@link CallbackInfo#isCancelled()} and {@link CallbackInfoReturnable#getReturnValue()} methods to see if the wrapped
+ * handler cancelled, so you can respond accordingly.
+ * <p>
+ * See <a href="https://github.com/LlamaLad7/MixinExtras/wiki/Cancellable">the wiki article</a> for more info.
+ */
 @Target(ElementType.PARAMETER)
 @Retention(RetentionPolicy.CLASS)
 public @interface Cancellable {