fix: ignore .github and Docs directories at export (zip)

[JamesRezo]

To avoid the files below to be downloaded and installed when using composer

vendor/cerdic/css-tidy/.github/workflows/build.yml
vendor/cerdic/css-tidy/Docs/__filesource/fsource_csstidy__class.csstidy.php.html
vendor/cerdic/css-tidy/Docs/__filesource/fsource_csstidy__class.csstidy_optimise.php.html
vendor/cerdic/css-tidy/Docs/__filesource/fsource_csstidy__class.csstidy_print.php.html
vendor/cerdic/css-tidy/Docs/__filesource/fsource_csstidy__data.inc.php.html
vendor/cerdic/css-tidy/Docs/classtrees_csstidy.html
vendor/cerdic/css-tidy/Docs/csstidy/_class_csstidy_optimise_php.html
vendor/cerdic/css-tidy/Docs/csstidy/_class_csstidy_php.html
vendor/cerdic/css-tidy/Docs/csstidy/_class_csstidy_print_php.html
vendor/cerdic/css-tidy/Docs/csstidy/_data_inc_php.html
vendor/cerdic/css-tidy/Docs/csstidy/csstidy.html
vendor/cerdic/css-tidy/Docs/csstidy/csstidy_optimise.html
vendor/cerdic/css-tidy/Docs/csstidy/csstidy_print.html
vendor/cerdic/css-tidy/Docs/elementindex.html
vendor/cerdic/css-tidy/Docs/elementindex_csstidy.html
vendor/cerdic/css-tidy/Docs/errors.html
vendor/cerdic/css-tidy/Docs/index.html
vendor/cerdic/css-tidy/Docs/li_csstidy.html
vendor/cerdic/css-tidy/Docs/media/background.png
vendor/cerdic/css-tidy/Docs/media/empty.png
vendor/cerdic/css-tidy/Docs/media/style.css
vendor/cerdic/css-tidy/Docs/todolist.html