[gnome-builder] view: add some docs on the editor view

[Christian Hergert <chergert src gnome org>]

commit 78ce12844ca2d4f8182f4e8efdf9bdc486d07d4e
Author: Christian Hergert <chergert redhat com>
Date:   Wed Sep 6 17:39:30 2017 -0700

    view: add some docs on the editor view

 doc/plugins/editor/view.rst |   53 +++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 53 insertions(+), 0 deletions(-)
---
diff --git a/doc/plugins/editor/view.rst b/doc/plugins/editor/view.rst
index 50c0ec1..d2c47e2 100644
--- a/doc/plugins/editor/view.rst
+++ b/doc/plugins/editor/view.rst
@@ -8,3 +8,56 @@ Implementing this interface allows you to be notified whenever a new view is cre
 
 Additionally, if you only want your plugin to be enabled when certain languages are active, you can set the 
``X-Editor-View-Languages=c,cplusplus`` keyword in your ``.plugin`` file.
 In the example provided, the plugin interface would be enabled for ``C`` and ``C++`` files.
+
+.. code-block:: python3
+
+   # my_plugin.py
+
+   import gi
+
+   from gi.repository import GObject
+   from gi.repository import Gtk
+   from gi.repository import GtkSource
+   from gi.repository import Ide
+
+   class MyEditorViewAddin(GObject.Object, Ide.EditorViewAddin):
+
+       def do_load(self, view):
+           """
+           @view is an Ide.EditorView which contains the buffer and sourceview.
+           """
+
+           # You get get the Ide.Buffer using
+           buffer = view.get_buffer()
+
+           # Or the Ide.SourceView widget
+           source_view = view.get_view()
+
+           # Toggle the overview map
+           view.set_show_map(True)
+           view.set_auto_hide_map(True)
+
+           # Scroll to a given line
+           view.scroll_to_line(100)
+
+           # Change the language
+           lang = GtkSource.LanguageManager.get_default().get_language('c')
+           view.set_language(lang)
+
+           # Jump to the next error
+           view.move_next_error()
+
+           # Jump to the next search result
+           view.move_next_search_result()
+
+       def do_unload(self, view):
+           """
+           This should undo anything you setup when loading the addin.
+           """
+
+       def do_language_changed(self, lang_id):
+           print("language was changed to", lang_id)
+
+       def do_stack_set(self, stack):
+           print("View was moved to document stack", stack)
+