docs: fix links (#334)

Author: suruaku

README.md

@@ -19,10 +19,12 @@ Do you need a real-world example that uses this router? Check out [Fastify](http
     - [Supported path formats](#supported-path-formats)
     - [Match order](#match-order)
     - [Supported methods](#supported-methods)
-  - [off(method, path)](#offmethod-path)
-    - [off(methods[], path)](#offmethods-path)
-    - [off(methods, path, [constraints])](#offmethods-path-constraints)
-  - [lookup(request, response, [context], [done])](#lookuprequest-response-context)
+  - [off(methods[], path, [constraints])](#offmethods-path-constraints)
+    - [off(methods, path)](#offmethods-path)
+    - [off(methods, path, constraints)](#offmethods-path-constraints-1)
+    - [off(methods[], path)](#offmethods-path-1)
+    - [off(methods[], path, constraints)](#offmethods-path-constraints-2)
+  - [lookup(request, response, [context], [done])](#lookuprequest-response-context-done)
   - [find(method, path, [constraints])](#findmethod-path-constraints)
   - [prettyPrint([{ method: 'GET', commonPrefix: false, includeMeta: true || [] }])](#prettyprint-commonprefix-false-includemeta-true---)
   - [reset()](#reset)