hljs.registerLanguage('impetus', function(hljs) {
    return {
        case_insensitive: true,
        contains: [
            {
                className: 'keyword',
                begin: '^\\*',
                end: '$'
            },
            {
                className: 'number',
                begin: '\\b\\d+(\\.\\d+)?([eE][+-]?\\d+)?\\b'
            },
            {
                className: 'comment',
                begin: '#'
            }
        ]
    };
});

// Attach this to mdBook in your book.toml
hljs.initHighlightingOnLoad();
