Viewer: choose syntax highlighting theme This release come with 3 new configuration features: 1. Choose the syntax highlighting theme with the configuration file variables: `tmpl_html.viewer_highlighting_theme` and `tmpl_html.exporter_highlighting_theme`. 2. Breaking change: The HTML templates `tmpl_html.viewer`, `tmpl_html.viewer_error` and `tmpl_html.exporter` automatically escape HTML critical characters. Escaping can be disabled be adding the `safe` filter in last position. 3. Tp-Note's configuration file is now stored with inline documentation.