Documentation: ANDROID_EXTRA_PLUGINS needs additional information

bool copyAndroidExtraResources(const Options &options)
{
    if (options.extraPlugins.isEmpty())
        return true;

    if (options.verbose)
        fprintf(stdout, "Copying %d external resources to package.\n", options.extraPlugins.size());

    for (const QString &extraResource : options.extraPlugins) {
        QFileInfo extraResourceInfo(extraResource);
        if (!extraResourceInfo.exists() || !extraResourceInfo.isDir()) {
            fprintf(stderr, "External resource %s does not exist or not a correct directory!\n", qPrintable(extraResource));
            return false;
        }

        QDir resourceDir(extraResource);
        QString assetsDir = options.outputDirectory + QStringLiteral("/assets/") + resourceDir.dirName() + QLatin1Char('/');
        QString libsDir = options.outputDirectory + QStringLiteral("/libs/") + options.architecture + QLatin1Char('/');

        const QStringList files = allFilesInside(resourceDir, resourceDir);
        for (const QString &resourceFile : files) {
            QString originFile(resourceDir.filePath(resourceFile));
            QString destinationFile;
            if (!resourceFile.endsWith(QLatin1String(".so"))) {
                destinationFile = assetsDir + resourceFile;
            } else {
                destinationFile = libsDir + QStringLiteral("/lib") + QString(resourceDir.dirName() + QLatin1Char('/') + resourceFile).replace(QLatin1Char('/'), QLatin1Char('_'));
            }

            if (!copyFileIfNewer(originFile, destinationFile, options.verbose))
                return false;
        }
    }

    return true;
}