Add etcd version scanner docs

documentation/modules/auxiliary/scanner/etcd/version.md

@@ -0,0 +1,38 @@
+## Vulnerable Application
+
+etcd is a distributed reliable key-value store.  It exposes and API from which you can obtain the version of etcd and related components.
+
+### Docker
+
+  1. `docker run -p 2379:2379 miguelgrinberg/easy-etcd`
+
+## Verification Steps
+
+  1. Install the application
+  2. Start msfconsole
+  3. Do: ```use auxiliary/scanner/etcd/version```
+  4. Do: ```set rhosts [IPs]```
+  5. Do: ```run```
+  6. You should get a JSON response for the version and the service identified in `services`.
+
+## Scenarios
+
+### etcd in Docker
+
+```
+msf5 > use auxiliary/scanner/etcd/version
+msf5 auxiliary(scanner/etcd/version) > set RHOSTS localhost
+RHOSTS => localhost
+msf5 auxiliary(scanner/etcd/version) > run
+
+[+] 127.0.0.1:2379       : {"etcdserver"=>"3.1.3", "etcdcluster"=>"3.1.0"}
+[*] Scanned 1 of 1 hosts (100% complete)
+[*] Auxiliary module execution completed
+msf5 auxiliary(scanner/etcd/version) > services
+Services
+========
+
+host       port  proto  name  state  info
+----       ----  -----  ----  -----  ----
+127.0.0.1  2379  tcp    etcd  open   {"etcdserver"=>"3.1.3", "etcdcluster"=>"3.1.0"}
+```