rename documentation version to toolchain version

Author: mateoconlechuga

docs/templates/versions.html

@@ -1,7 +1,7 @@
 {% if display_lower_left %}
   <div class="rst-versions" data-toggle="rst-versions" role="note" aria-label="versions">
     <span class="rst-current-version" data-toggle="rst-current-version">
-      <span class="fa fa-book"> Documentation Version</span>
+      <span class="fa fa-book"> Toolchain Version</span>
       {{ current_version }}
       <span class="fa fa-caret-down"></span>
     </span>