Fix normalization to join adjacent text nodes

src/models/node.js

@@ -982,6 +982,7 @@ const Node = {
 
   /**
    * Join a node by `key` with another `withKey`.
+   * It brings Node<key> after Node<WithKey>
    *
    * @param {String} key
    * @param {String} withKey

src/plugins/schema.js

@@ -112,7 +112,7 @@ const NO_ADJACENT_TEXT_RULE = {
   normalize: (transform, node, pairs) => {
     return pairs.reduce((t, pair) => {
       const [ first, second ] = pair
-      return t.joinNodeByKey(first.key, second.key)
+      return t.joinNodeByKey(second.key, first.key)
     }, transform)
   }
 }