doc: Add theme installation instructions
doc: Add theme installation instructions
Pilskalns/hugo-theme-docdock,Xipas/hugo-theme-learn,vjeantet/hugo-theme-docdock,Xipas/hugo-theme-learn,jshook/hugo-theme-learn,matcornic/hugo-theme-learn,SKuipers/hugo-theme-gibbon,matcornic/hugo-theme-learn,Pilskalns/hugo-theme-docdock,SKuipers/hugo-theme-gibbon,jshook/hugo-theme-learn,vjeantet/hugo-theme-docdock