docs: add plugin manager installation examples

README.md

@@ -108,7 +108,7 @@ I recommend adjusting your terminal's background color to the one used in Appren
 
 ## Installing Apprentice
 
-Colorschemes must be placed in a directory named `colors` that is somewhere in Vim’s `runtimepath`:
+Colorschemes must be placed in a directory named `colors` that is somewhere in Vim's `runtimepath`:
 
 The canonical location is:
 
@@ -126,6 +126,38 @@ or:
 
 or whatever works for you.
 
+### Plugin managers
+
+If you use a plugin manager, here are examples for the most common ones:
+
+**vim-plug** `~/.vimrc`:
+
+```vim
+Plug 'romainl/Apprentice'
+```
+
+**dein.nvim** `~/.vimrc`:
+
+```vim
+call dein#add('romainl/Apprentice')
+```
+
+**lazy.nvim** `~/.config/nvim/init.lua`:
+
+```lua
+require('lazy').setup({
+  { 'romainl/Apprentice' },
+})
+```
+
+**packer.nvim** `~/.config/nvim/lua/plugins.lua`:
+
+```lua
+return require('packer').startup(function()
+  use 'romainl/Apprentice'
+end)
+```
+
 Arch users may be happy to hear that Apprentice [has landed in AUR](https://aur.archlinux.org/packages/vim-apprentice-git/). To install it, use an AUR helper:
 
     $ yay -S vim-apprentice-git