update(theme): update theme version to hugo-geekdoc v0.18.2

themes/hugo-geekdoc/.chglog/CHANGELOG.tpl.md

themes/hugo-geekdoc/.chglog/config.yml

themes/hugo-geekdoc/.npmrc

themes/hugo-geekdoc/CONTRIBUTING.md

themes/hugo-geekdoc/VERSION

themes/hugo-geekdoc/assets/js/search.js

themes/hugo-geekdoc/assets/sprites/geekdoc.svg

themes/hugo-geekdoc/data/assets.json

themes/hugo-geekdoc/layouts/404.html

themes/hugo-geekdoc/layouts/_default/baseof.html

themes/hugo-geekdoc/layouts/_default/list.html

themes/hugo-geekdoc/layouts/partials/content.html

themes/hugo-geekdoc/layouts/partials/menu-bundle.html

themes/hugo-geekdoc/layouts/partials/menu-extra.html

themes/hugo-geekdoc/layouts/partials/menu-filetree.html

themes/hugo-geekdoc/layouts/partials/menu.html

themes/hugo-geekdoc/layouts/partials/page-header.html

themes/hugo-geekdoc/layouts/partials/site-footer.html

themes/hugo-geekdoc/layouts/partials/site-header.html

themes/hugo-geekdoc/layouts/posts/list.html