Review converter.py documentation.

docs/api/generated/plugin_dbui.converter.to_field.rst

docs/api/generated/plugin_dbui.converter.to_fields.rst

docs/api/generated/plugin_dbui.converter.to_formPanel.rst

docs/api/generated/plugin_dbui.converter.to_gridColumn.rst

...pi/generated/plugin_dbui.converter.to_gridColumnModel.rst

docs/api/generated/plugin_dbui.converter.to_gridFilter.rst

docs/api/generated/plugin_dbui.converter.to_gridPanel.rst

docs/api/generated/plugin_dbui.converter.to_jsonstore.rst

docs/api/generated/plugin_dbui.converter.to_model.rst

...nerated/plugin_dbui.converter.to_panelWithUrlSelector.rst

docs/api/generated/plugin_dbui.converter.to_treeNodes.rst

docs/api/generated/plugin_dbui.converter.to_viewport.rst

modules/plugin_dbui/converter.py