vim,zathura: Setup LaTeX file development

LaTeX files can now be automatically compiled in vim and jumping into
the relevant lines from PDF to code or the other way around is possible
too.
Add the LaTeX coc-language server as well.

Thanks to @AurelWeinhold

.config/vim/vimrc

@@ -1,11 +1,13 @@
 " Set leader key
 let mapleader = "\<Space>"
+let maplocalleader = mapleader
 
 " Plugins ######################################################################
 " Auto completion
 " needs vim >= 8.1.1719 to support features like popup and text property.
 if (has('patch-8.1.1719') || has('nvim'))
-	let g:coc_global_extensions = ['coc-clangd', 'coc-sh', 'coc-python']
+	let g:coc_global_extensions =
+		\ ['coc-clangd', 'coc-sh', 'coc-python', 'coc-vimtex']
 	packadd! coc.nvim
 	source $XDG_CONFIG_HOME/vim/coc.nvim.vim
 endif
@@ -17,6 +19,9 @@ packadd! fzf.vim
 nmap <leader>f :Files<CR>
 " Theme
 packadd! onedark.vim
+" LaTeX
+packadd! vimtex
+source $XDG_CONFIG_HOME/vim/vimtex.vim
 " Git information
 packadd! vim-gitgutter
 " Surround text with parentheses, brackets, quotes, tags, etc.