n-api: fix section title typo

PR-URL: https://github.com/nodejs/node/pull/13972
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

doc/api/n-api.md

@@ -41,7 +41,7 @@ The documentation for N-API is structured as follows:
 * [Working with JavaScript Properties][]
 * [Working with JavaScript Functions][]
 * [Object Wrap][]
-* [Aynchronous Operations][]
+* [Asynchronous Operations][]
 
 The N-API is a C API that ensures ABI stability across Node.js versions
 and different compiler levels. However, we also understand that a C++