Replace the deprecated third-party memcached_exporter by the official one

content/docs/instrumenting/exporters.md

@@ -24,6 +24,7 @@ These exporters are maintained as part of the official
    * [HAProxy exporter](https://github.com/prometheus/haproxy_exporter)
    * [InfluxDB exporter](https://github.com/prometheus/influxdb_exporter)
    * [JMX exporter](https://github.com/prometheus/jmx_exporter)
+   * [Memcached exporter](https://github.com/prometheus/memcached_exporter)
    * [Mesos task exporter](https://github.com/prometheus/mesos_exporter)
    * [MySQL server exporter](https://github.com/prometheus/mysqld_exporter)
    * [SNMP exporter](https://github.com/prometheus/snmp_exporter)
@@ -53,7 +54,6 @@ hosted outside of the Prometheus GitHub organization.
    * [IoT Edison exporter](https://github.com/roman-vynar/edison_exporter)
    * [Jenkins exporter](https://github.com/RobustPerception/python_examples/tree/master/jenkins_exporter)
    * [knxd exporter](https://github.com/RichiH/knxd_exporter)
-   * [Memcached exporter](https://github.com/Snapbug/memcache_exporter)
    * [Meteor JS web framework exporter](https://atmospherejs.com/sevki/prometheus-exporter)
    * [Minecraft exporter module](https://github.com/Baughn/PrometheusIntegration)
    * [Mirth Connect exporter](https://github.com/vynca/mirth_exporter)