Refactor neovim config (#2)

Changes include:

- [x] Use init.lua instead of init.vim
   - Some keybindings are still to be converted
- [x] Use packer as a package manager instead of vim-plug
- [ ] Use built-in lsp instead of coc.nvim
   - [x] Set up language servers
   - [x] Completion
   - [x] Formatting (previously coc-prettier, now neoformat)
   - [ ] Snippets
- [ ] Replace fzf with telescope.nvim
- [x] Implement treesitter syntax highlighting
   - More info: https://github.com/nvim-treesitter/nvim-treesitter

Note that this requires neovim nightly until 0.5 is released

Reviewed-on: #2
Co-authored-by: Marko Korhonen <marko@korhonen.cc>
Co-committed-by: Marko Korhonen <marko@korhonen.cc>

home/.config/nvim/init.lua

@@ -0,0 +1,13 @@
+require 'pluginmanager'
+require 'autocmd'
+require 'keybinds'
+require 'settings'
+
+-- Plugin configurations
+require 'pluginconf.lualine'
+require 'pluginconf.bufferline'
+require 'pluginconf.completion'
+require 'pluginconf.lsp'
+require 'pluginconf.treesitter'
+require 'pluginconf.telescope'
+-- require 'pluginconf.indent-blankline'