1.2.2 - rename partials

Just a tech update to tidy up partial files, but it may be breaking for users who overrode partial files.

If you overrode any partial files, please check your files don't contain old names.

List of renamed partials:
layouts/partials/fontawesome.html -> layouts/partials/font-awesome.html
layouts/partials/languageSelect.html -> layouts/partials/language-switcher.html
layouts/partials/postInfo.html -> layouts/partials/post-info.html
layouts/partials/paginationPost.html -> layouts/partials/post-pagination.html
layouts/partials/postSummary.html -> layouts/partials/post-summary.html
layouts/partials/themeSwitcher.html -> layouts/partials/theme-switcher.html