Delete another nvim completion deprecated plugin

This is yet another nvim completion plugin that got deprecated and
archived, due to the lack of maintainers, by its' author.  Therefore the
submodule is being deleted from this repo.

.gitmodules

@@ -34,9 +34,6 @@
 	url = https://github.com/neovim/nvim-lspconfig.git
 	shallow = true
 	ignore = all
-[submodule "nvim/pack/misc/start/completion-nvim"]
-	path = nvim/pack/lsp/start/completion-nvim
-	url = https://github.com/nvim-lua/completion-nvim.git
 [submodule "nvim/pack/lsp/start/nvim-cmp"]
 	path = nvim/pack/lsp/start/nvim-cmp
 	url = https://github.com/hrsh7th/nvim-cmp.git

nvim/language_server.vim

@@ -63,13 +63,7 @@ for _, lsp in ipairs(servers) do
 end
 EOF
 
-" completion-nvim
-"autocmd FileType python,c lua require('completion').on_attach()
-let g:completion_matching_strategy_list = ['exact', 'substring', 'fuzzy']
-let g:completion_matching_ignore_case = 1  " not v:true, 1. ¯\_(ツ)_/¯
-let g:completion_matching_smart_case = 1  " not v:true, 1. ¯\_(ツ)_/¯
-let g:completion_trigger_on_delete = 1  " not v:true, 1. ¯\_(ツ)_/¯
-
+" cmp
 " Setup buffer configuration (nvim-lua source only enables in Lua filetype).
 autocmd FileType gitcommit lua require'cmp'.setup.buffer {
 \   sources = {

nvim/pack/lsp/start/completion-nvim

@@ -1 +0,0 @@
-Subproject commit 22624f0aa5d1fdd0c84456300d2390b223c1a226