Add describedBy to commands (#782)

* Add `describedBy` to commands

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: jtpio

packages/base/src/3dview/mainview.tsx

@@ -210,6 +210,12 @@ export class MainView extends React.Component<IProps, IStates> {
   addContextMenu = (): void => {
     const commands = new CommandRegistry();
     commands.addCommand('add-annotation', {
+      describedBy: {
+        args: {
+          type: 'object',
+          properties: {}
+        }
+      },
       execute: () => {
         if (!this._pointer3D) {
           return;