docs: link to benchmark

Author: gajus

README.md

@@ -31,7 +31,7 @@ await pg.query('SELECT $1::text as name', ['foo']);
 
 ## Motivation
 
-`postgres` is leaner/faster implementation of PostgreSQL protocol in Node.js than `pg`. However, `postgres` API is very different from the more broadly adopted [`pg` client](https://www.npmjs.com/package/pg). This package allows to adopt `postgres` without going through a painful migration. In particular, this compatibility layer has been designed to allow adoption of `postgres` using [Slonik PostgreSQL client](https://www.npmjs.com/package/slonik).
+`postgres` is leaner/[faster](https://github.com/porsager/postgres-benchmarks) implementation of PostgreSQL protocol in Node.js than `pg`. However, `postgres` API is very different from the more broadly adopted [`pg` client](https://www.npmjs.com/package/pg). This package allows to adopt `postgres` without going through a painful migration. In particular, this compatibility layer has been designed to allow adoption of `postgres` using [Slonik PostgreSQL client](https://www.npmjs.com/package/slonik).
 
 ## Scope