code: def setup(app):
      """
      Install the plugin.
  
      :param app: Sphinx application context.
      """
      app.add_role("ghissue", ghissue_role)
      app.add_role("ghpull", ghissue_role)
      app.add_role("ghuser", ghuser_role)
      app.add_role("ghcommit", ghcommit_role)
      app.add_config_value("github_project_url", None, "env")
  
      metadata = {
          "parallel_read_safe": True,
          "parallel_write_safe": True,
      }
      return metadata
  
imports: from docutils import nodes, utils
  from docutils.parsers.rst.roles import set_classes
label_desc: Use image node_id 5 for calling a global function with example usage: setup(app) and returns: metadata