fix: load matchers from jasmine-expect

I accidentally removed this in 41ac86129b9b45216708c307645a0fc47eecf8bf, resulting in much breakage.

packages/jsdoc-test-matchers/index.js

@@ -1,6 +1,9 @@
 const _ = require('lodash');
 const { addMatchers } = require('add-matchers');
 
+// Adds matchers from https://github.com/JamieMason/Jasmine-Matchers.
+require('jasmine-expect');
+
 addMatchers({
   toBeError(value) {
     return value instanceof Error;