private void copyToZipFile(String dir, File iconFile, ZipOutputStream zos) throws IOException {
		ZipEntry entry = new ZipEntry(dir + "images/" + iconFile.getName());
		zos.putNextEntry(entry);
		Files.copy(iconFile.toPath(), zos);
	}
Writes the theme to the given file in a zip format.
@param file the file to write to
@throws IOException if an I/O error occurs trying to write the file
Ghidra/Framework/Gui/src/main/java/generic/theme/ThemeWriter.java