Update COC settings

- Add ccls
- Update coc-spell-checker
- Update theme
diff --git a/modules/neovim/coc/theme.vim b/modules/neovim/coc/theme.vim
index d7558f1..7caa2a2 100644
--- a/modules/neovim/coc/theme.vim
+++ b/modules/neovim/coc/theme.vim
@@ -3,10 +3,10 @@
 call g:Highlight("DiagnosticWarn", g:yellow, g:transparent)
 call g:Highlight("DiagnosticError", g:red, g:transparent)
 
-highlight DiagnosticUnderlineError guisp=#e06c75
-highlight DiagnosticUnderlineInfo  guisp=#61afef
-highlight DiagnosticUnderlineHint  guisp=#61afef
-highlight DiagnosticUnderlineWarn  guisp=#e5c07b
+au ColorScheme onehalfdark highlight DiagnosticUnderlineError guisp=#e06c75
+au ColorScheme onehalfdark highlight DiagnosticUnderlineInfo  guisp=#61afef
+au ColorScheme onehalfdark highlight DiagnosticUnderlineHint  guisp=#61afef
+au ColorScheme onehalfdark highlight DiagnosticUnderlineWarn  guisp=#e5c07b
 
 call g:Highlight("CocPumMenu", g:transparent, g:black)
 call g:Highlight("CocFloating", g:transparent, g:black)