Provide a walkthrough for inline edit

Once this change is merged, the rendered markdown can be linked to in
the official GWTUI deprecation announcement.

TODO: find out the way to include this documentation in the final
artifact (release.war)

Bug: Issue 8267
Change-Id: I4a1be9e7eb6512507819658bc124fc993a07e4eb

Documentation/dev-polygerrit.txt

@@ -1,13 +1,7 @@
 = PolyGerrit - GUI
 
 [IMPORTANT]
-PolyGerrit is still a beta feature...
+PolyGerrit is still a beta feature. Some features may be missing.
-
-Missing features in PolyGerrit:
-
-- Inline Edit
-
-- And many more features missing.
 
 == Configuring
 

polygerrit-ui/edit-walkthrough/edit-walkthrough.md

@@ -0,0 +1,80 @@
+# In-browser Editing in Gerrit
+
+### What's going on?
+
+Until Q1 of 2018, editing a file in the browser was not supported by Gerrit's
+new UI. This feature is now done and ready for use.
+
+Read on for a walkthrough of the feature!
+
+### Creating an edit
+
+Click on the "Edit" button to begin.
+
+One may also go to the project mmanagement page (Browse => Repository =>
+Commands => Create Change) to create a new change.
+
+![](./img/into_edit.png)
+
+### Performing an action
+
+The buttons in the file list header open dialogs to perform actions on any file
+in the repo.
+
+*   Open - opens an existing or new file from the repo in an editor.
+*   Delete - deletes an existing file from the repo.
+*   Rename - renames an existing file in the repo.
+
+To leave edit mode and restore the normal buttons to the file list, click "Stop
+editing".
+
+![](./img/in_edit_mode.png)
+
+### Performing an action on a file
+
+The "Actions" dropdown appears on each file, and is used to perform actions on
+that specific file.
+
+*   Open - opens this file in the editor.
+*   Delete - deletes this file from the repo.
+*   Rename - renames this file in the repo.
+*   Restore - restores this file to the state it existed in at the patch the
+edit was created on.
+
+![](./img/actions_overflow.png)
+
+### Modifying the file
+
+This is the editor view.
+
+Clicking on the file path allows you to rename the file, You can edit code in
+the textarea, and "Close" will discard any unsaved changes and navigate back to
+the previous view.
+
+![](./img/in_editor.png)
+
+### Saving the edit
+
+You can save changes to the code with `cmd+s`, `ctrl+s`, or by clicking the
+"Save" button.
+
+![](./img/edit_made.png)
+
+### Publishing the edit
+
+You may publish or delete the edit by clicking the buttons in the header.
+
+
+
+![](./img/edit_pending.png)
+
+### What if I have questions not answered here?
+
+Gerrit's [official docs](https://gerrit-review.googlesource.com/Documentation/user-inline-edit.html)
+are in the process of being updated and largely refer to the old UI, but the
+user experience is largely the same.
+
+Otherwise, please email
+[the repo-discuss mailing list](mailto:repo-discuss@google.com) or file a bug
+on Gerrit's official bug tracker,
+[Monorail](https://bugs.chromium.org/p/gerrit/issues/entry?template=PolyGerrit+Issue).