docs(contribute): link compiler docs in writing-a-plugin (#1700)

While authoring plugins the list of hooks is essential knowledge, so a 
link to hooks documentation page should be accessible in the top of 
writing a plugin guide.

Author: chrmod

src/content/contribute/writing-a-plugin.md

@@ -11,7 +11,7 @@ A plugin for `webpack` consists of
 
 - A named JavaScript function.
 - Defines `apply` method in it's prototype.
-- Specifies webpack's event hook to attach itself.
+- Specifies an [event hook](/api/compiler/#event-hooks) on which to bind itself.
 - Manipulates webpack internal instance specific data.
 - Invokes webpack provided callback after functionality is complete.