Drop UltiSnips and move to coc-snippets

Also change the completion confirm mapping to <TAB> and make the
priority of snippets higher.

coc-settings.json

@@ -7,6 +7,7 @@
   "diagnostic.infoSign": "▸",
   "diagnostic.warningSign": "▸",
   "powershell.integratedConsole.showOnStartup": false,
+  "snippets.priority": 100,
   "suggest.noselect": true,
   "yaml.schemas": {
     "https://gitlab.com/gitlab-org/gitlab/-/raw/master/app/assets/javascripts/editor/schema/ci.json": [

plugin/mappings.vim

@@ -1,12 +1,13 @@
 " coc.nvim
-nmap <silent> <leader>fi <Plug>(coc-fix-current)
-nmap <silent> <leader>gd <Plug>(coc-definition)
-nmap <silent> <leader>gt <Plug>(coc-type-definition)
-nmap <silent> <leader>sd <Plug>(coc-diagnostic-info)
-nmap <silent> <leader>gr <Plug>(coc-references)
-nmap <silent> K :call do#show_documentation()<CR>
-nmap <silent> <C-n> <Plug>(coc-diagnostic-next)
-nmap <silent> <C-p> <Plug>(coc-diagnostic-prev)
+inoremap <silent><expr> <TAB> coc#pum#visible() ? coc#pum#confirm() : "\<TAB>"
+nnoremap <silent> <leader>fi <Plug>(coc-fix-current)
+nnoremap <silent> <leader>gd <Plug>(coc-definition)
+nnoremap <silent> <leader>gt <Plug>(coc-type-definition)
+nnoremap <silent> <leader>sd <Plug>(coc-diagnostic-info)
+nnoremap <silent> <leader>gr <Plug>(coc-references)
+nnoremap <silent> K :call do#show_documentation()<CR>
+nnoremap <silent> <C-n> <Plug>(coc-diagnostic-next)
+nnoremap <silent> <C-p> <Plug>(coc-diagnostic-prev)
 
 if has('nvim')
   " Make nvim :terminal more like vim :terminal

tasks.yaml

@@ -7,8 +7,7 @@
       # Conqueror of Completion
       - repo: neoclide/coc.nvim
         branch: release
-      # Snippet engine & snippets
-      - repo: SirVer/ultisnips
+      # Snippet collection
       - repo: honza/vim-snippets
       # Completion for vimscript
       - repo: vim-scripts/vimomni

vimrc

@@ -59,7 +59,7 @@ let g:coc_global_extensions = [
 \   'coc-json',
 \   'coc-marketplace',
 \   'coc-pyright',
-\   'coc-ultisnips',
+\   'coc-snippets',
 \   'coc-vimlsp',
 \   'coc-yaml',
 \]