text: """
  Sphinx extension to add ReadTheDocs-style "Edit on GitHub" links to the
  sidebar.
  Loosely based on https://github.com/astropy/astropy/pull/347
  
  Modified by NEM to get the feedback url.
  """
  
  import os
  import warnings
  
  
  __licence__ = 'BSD (3 clause)'
  
  
  def get_github_url(app, view, path):
      return 'https://github.com/{project}/{view}/{branch}/source/{path}'.format(
          project=app.config.edit_on_github_project,
          view=view,
          branch=app.config.edit_on_github_branch,
          path=path)
  
  def get_feedback_url(app):
      return 'https://github.com/{project}/issues/new/choose'.format(
          project=app.config.edit_on_github_project)
  
  def html_page_context(app, pagename, templatename, context, doctree):
      if templatename != 'page.html':
          return
  
      if not app.config.edit_on_github_project:
          warnings.warn("edit_on_github_project not specified")
          return
  
      path = os.path.relpath(doctree.get('source'), app.builder.srcdir)
      show_url = get_github_url(app, 'blob', path)
      edit_url = get_github_url(app, 'edit', path)
      feedback_url = get_feedback_url(app)
  
      context['show_on_github_url'] = show_url
      context['edit_on_github_url'] = edit_url
      context['feedback_on_github_url'] = feedback_url
  
  
  def setup(app):
      app.add_config_value('edit_on_github_project', '', True)
      app.add_config_value('edit_on_github_branch', 'master', True)
      app.connect('html-page-context', html_page_context)