Provide some documentation for a command.
function(command, arg) {
        var docs = [];
        docs.push('<strong><tt> &gt; ');
        docs.push(command.name);
        if (command.params && command.params.length > 0) {
            command.params.forEach(function(param) {
                if (param.defaultValue === undefined) {
                    docs.push(' [' + param.name + ']');
                }
                else {
                    docs.push(' <em>[' + param.name + ']</em>');
                }
            }, this);
        }
        docs.push('</tt></strong><br/>');

        docs.push(command.description ? command.description : '(No description)');
        docs.push('<br/>');

        if (command.params && command.params.length > 0) {
            docs.push('<ul>');
            command.params.forEach(function(param) {
                docs.push('<li>');
                docs.push('<strong><tt>' + param.name + '</tt></strong>: ');
                docs.push(param.description ? param.description : '(No description)');
                if (param.defaultValue === undefined) {
                    docs.push(' <em>[Required]</em>');
                }
                else if (param.defaultValue === null) {
                    docs.push(' <em>[Optional]</em>');
                }
                else {
                    docs.push(' <em>[Default: ' + param.defaultValue + ']</em>');
                }
                docs.push('</li>');
            }, this);
            docs.push('</ul>');
        }

        return new Hint(Status.VALID, docs.join(''), arg);
    }