chore: topics/k1ch/jsDoc for usherDb knex instance

database/layer/knex.js

@@ -1,5 +1,16 @@
 const knex = require('knex');
 const knexDbConfig = require('../knexfile');
+
+/**
+ * Usher DB connection instance.
+ * @name usherDb
+ * @type {import('knex')}
+ * @desc This instance provides a connection to the Usher database using Knex.js
+ * @example // To import usherDb instance
+ * const { usherDb } = require('./knex');
+ * @example // To perform a database query
+ * const persona = await usherDb('personas').where('key', personaKey).first();
+ */
 const usherDb = knex(knexDbConfig);
 
 module.exports = { usherDb }