Add documentation to addModalPanel api

spec/panel-container-element-spec.js

@@ -178,12 +178,12 @@ describe('PanelContainerElement', () => {
 
       it("focuses the first tabbable item if available", () => {
         const panel = createPanel()
-
         const panelEl = panel.getElement()
         const inputEl = document.createElement('input')
-        panelEl.appendChild(inputEl)
 
+        panelEl.appendChild(inputEl)
         expect(document.activeElement).not.toBe(inputEl)
+
         panel.show()
         expect(document.activeElement).toBe(inputEl)
       })

src/panel-container-element.js

@@ -51,7 +51,7 @@ class PanelContainerElement extends HTMLElement {
     if (this.model.isModal()) {
       this.hideAllPanelsExcept(panel)
       this.subscriptions.add(panel.onDidChangeVisible(visible => {
-        if (visible) this.hideAllPanelsExcept(panel)
+        if (visible) { this.hideAllPanelsExcept(panel) }
       }))
 
       if (panel.autoFocus) {

src/workspace.js

@@ -1752,6 +1752,11 @@ module.exports = class Workspace extends Model {
   //     (default: true)
   //   * `priority` (optional) {Number} Determines stacking order. Lower priority items are
   //     forced closer to the edges of the window. (default: 100)
+  //   * `autoFocus` (optional) {Boolean} true if you want modal focus managed for you by Atom.
+  //     Atom will automatically focus your modal panel's first tabbable element when the modal
+  //     opens and will restore the previously selected element when the modal closes. Atom will
+  //     also automatically restrict user tab focus within your modal while it is open.
+  //     (default: false)
   //
   // Returns a {Panel}
   addModalPanel (options = {}) {