Include extra-features documentation

README.md

@@ -20,6 +20,13 @@ To install on your Firefox browser, download the latest xpi file from [here](htt
 
 [service]: https://hypothes.is
 
+Extra features
+-----------
+As of v1.470.0.1, the Unofficial extension for Hypothesis enables some customization
+of the annotation client. Read more about it [here][extra-features].
+
+[extra-features]: docs/extra-features.md
+
 Known bugs
 -----------
 

docs/extra-features.md

@@ -0,0 +1,81 @@
+Extra features
+======================
+
+The Unofficial extension for Hypothesis enables some customization of the annotation
+client. Some of the configuration settings are supported by the official client and
+the unofficial extension simply lets you configure them. Others are experimental features
+only [supported][unofficial-client-config] by the unofficial client which the unofficial
+extension uses.
+
+
+[unofficial-client-config]: https://github.com/diegodlh/unofficial-hypothesis-client#client-configuration
+
+To change these settings, right-click the extension's button and click *Settings*.
+
+![Screenshot: right-click and click Settings](../src/help/new-features.png)
+
+Remember to reload the tabs you are annotating for the changes to take effect. In the
+future, some of these settings may be moved to the client's sidebar for easier
+configuration.
+
+This is the list of currently supported features. I already have other ideas in mind
+and I will be posting them [here][unofficial-ext-issues], and implementing them as time allows. Feel free to
+contribute your ideas as well!
+
+[unofficial-ext-issues]: https://github.com/diegodlh/unofficial-hypothesis-extension/issues
+
+#### Display current group name below the annotation adder
+
+When saving an annotation it is easy to tell from the sidebar what annotation group it 
+will be posted to. But when saving a highlight the sidebar remains closed and it may be
+unknowingly posted to the wrong group.
+
+This experimental feature shows the currently selected group name on the annotation adder
+toolbar.
+
+Choose “Except Public” to only show the group name if the currently selected group is not 
+the “Public” group.
+
+![Screenshot: group name shown on adder toolbar](../images/adderToolbarFooter.png)
+
+#### Make PDF overlay text white to aid in selection
+Hypothesis uses PDF.js to annotate PDFs. This viewer renders PDF documents as images of 
+the pages with a transparent layer of selectable text on top. Usually image and text 
+layers align perfectly. But sometimes (especially with scanned PDFs) they don’t and it 
+is hard to know exactly what is being selected for annotation. 
+
+This experimental feature shows the selected text in white for more accurate selection.
+
+![Screenshot: white text overlay on PDF](../images/usePdfWhiteOverlay.png)
+
+#### Transparent sidebar toolbar buttons
+
+The toolbar buttons may cover page content, especially at the top right corner of the 
+document. 
+
+This experimental feature (originally proposed [here][sidebar-buttons-transparent]) makes
+these buttons transparent.
+
+![Comparison opaque vs transparent buttons](../images/transparentToolbarButtons.png)
+
+[sidebar-buttons-transparent]: https://github.com/hypothesis/client/pull/1169
+
+#### Enable experimental New Page-Note button
+
+This enables setting the official `enableExperimentalNewNoteButton` config param from the
+browser extension.
+
+It adds a “New note” button in the Page Notes section of the sidebar. This button provides the 
+same functionality as the toolbar “New page note” button.
+
+![Experimental New Page-Note button](../images/expNewNoteButton.png)
+
+#### Open sidebar automatically on startup
+
+This enables setting the official `openSidebar` config param from the browser extension.
+
+It opens the annotation sidebar automatically when the extension is activated.
+
+
+
+