Add readme about illustration license

client/app/assets/images/illustrations/readme.md

@@ -0,0 +1,3 @@
+The illustrations shared in this folder are covered by the CC-BY-SA-NC-ND License v4.0 (or newer). You are allowed to use them when using unmodified versions of the Redash source code for non-commercial purposes (meaning for yourself), but you are not allowed to use for any other use or to distribute them as part of your software or fork of Redash.
+
+For any questions, please contact us.

client/app/components/empty-state/empty-state.html

@@ -6,7 +6,7 @@
         </h2>
       <p>{{$ctrl.description}}</p>
 
-      <img src="/static/images/{{$ctrl.illustration}}.svg" alt="{{$ctrl.illustration}} Illustration" width="75%">
+      <img src="/static/images/illustrations/{{$ctrl.illustration}}.svg" alt="{{$ctrl.illustration}} Illustration" width="75%">
     </div>
     <div class="empty-state__steps">
         <h4>Let's get started</h4>