nvim: cmp: add nvim completion for lua files

.config/nvim/lua/my/completion.lua

@@ -14,6 +14,7 @@ packer.use {
             'https://github.com/saadparwaiz1/cmp_luasnip',
             requires = 'https://github.com/L3MON4D3/LuaSnip'
         },
+        'https://github.com/hrsh7th/cmp-nvim-lua',
     },
     config = function()
         local cmp = require'cmp'
@@ -68,13 +69,15 @@ packer.use {
         })
 
         -- -- Set configuration for specific filetype.
-        -- cmp.setup.filetype('gitcommit', {
-        --     sources = cmp.config.sources({
-        --         { name = 'cmp_git' },
-        --     }, {
-        --         { name = 'buffer' },
-        --     })
-        -- })
+        cmp.setup.filetype('lua', {
+            sources = cmp.config.sources({
+                { name = 'nvim_lsp' },
+                { name = 'luasnip' },
+                { name = 'nvim_lua' },
+            }, {
+                { name = 'buffer' },
+            })
+        })
 
         -- Use buffer source for `/`
         cmp.setup.cmdline('/', {