style(init): Modularize entire init.lua

Now each plugin is in it's own seperate file that returns the plugin and
it's configs. This makes it simpler for me apply lazy loading to this
config.

Settings, Keymaps, Yank-highlight are inside kickstart directory within
their seperate files.

lua/kickstart/plugins/nvim-cmp.lua

@@ -0,0 +1,69 @@
+return {
+  -- Autocompletion
+  'hrsh7th/nvim-cmp',
+  dependencies = {
+    -- Snippet Engine & its associated nvim-cmp source
+    'L3MON4D3/LuaSnip',
+    'saadparwaiz1/cmp_luasnip',
+
+    -- Adds LSP completion capabilities
+    'hrsh7th/cmp-nvim-lsp',
+    'hrsh7th/cmp-path',
+
+    -- Adds a number of user-friendly snippets
+    'rafamadriz/friendly-snippets',
+  },
+  config = function()
+    -- [[ Configure nvim-cmp ]]
+    -- See `:help cmp`
+    local cmp = require 'cmp'
+    local luasnip = require 'luasnip'
+    require('luasnip.loaders.from_vscode').lazy_load()
+    luasnip.config.setup {}
+
+    cmp.setup {
+      snippet = {
+        expand = function(args)
+          luasnip.lsp_expand(args.body)
+        end,
+      },
+      completion = {
+        completeopt = 'menu,menuone,noinsert',
+      },
+      mapping = cmp.mapping.preset.insert {
+        ['<C-n>'] = cmp.mapping.select_next_item(),
+        ['<C-p>'] = cmp.mapping.select_prev_item(),
+        ['<C-b>'] = cmp.mapping.scroll_docs(-4),
+        ['<C-f>'] = cmp.mapping.scroll_docs(4),
+        ['<C-Space>'] = cmp.mapping.complete {},
+        ['<CR>'] = cmp.mapping.confirm {
+          behavior = cmp.ConfirmBehavior.Replace,
+          select = true,
+        },
+        ['<Tab>'] = cmp.mapping(function(fallback)
+          if cmp.visible() then
+            cmp.select_next_item()
+          elseif luasnip.expand_or_locally_jumpable() then
+            luasnip.expand_or_jump()
+          else
+            fallback()
+          end
+        end, { 'i', 's' }),
+        ['<S-Tab>'] = cmp.mapping(function(fallback)
+          if cmp.visible() then
+            cmp.select_prev_item()
+          elseif luasnip.locally_jumpable(-1) then
+            luasnip.jump(-1)
+          else
+            fallback()
+          end
+        end, { 'i', 's' }),
+      },
+      sources = {
+        { name = 'nvim_lsp' },
+        { name = 'luasnip' },
+        { name = 'path' },
+      },
+    }
+  end,
+}