add version chooser icon top right

src/mesh/api.js

@@ -540,6 +540,10 @@ const api = exports({
         window.open("https://docs.grid.space/projects/mesh-tool");
     },
 
+    version() {
+        window.location = "/choose";
+    },
+
     clear() {
         for (let group of group.list()) {
             group.remove(group);

src/mesh/build.js

@@ -226,6 +226,9 @@ function ui_build() {
 
     // add a help button
     h.bind($('top-right'), [
+        h.div({ id: "top-version", onclick: api.version }, [
+            h.div({ class: "fas fa-hashtag" }),
+        ]),
         h.div({ id: "top-settings", onclick: api.settings }, [
             h.div({ class: "fas fa-sliders-h" }),
         ]),