create matrix config subsection

config.sample.yaml

@@ -1,3 +1,4 @@
+matrix:
   baseurl: 'https://example.org'
   accesstoken: 't0ps3cr3t'
   userid: '@jd:example.org'

index.js

@@ -5,9 +5,9 @@ const yaml = require('js-yaml');
 
 const config = yaml.safeLoad(fs.readFileSync('config.yaml'));
 const matrixclient = sdk.createClient({
-    baseUrl: config.baseurl,
-    accessToken: config.accesstoken,
-    userId: config.userid
+    baseUrl: config.matrix.baseurl,
+    accessToken: config.matrix.accesstoken,
+    userId: config.matrix.userid
 });
 const ssh = new node_ssh();