add docu in readme to install/setup using vim-plug

README.md

@@ -42,6 +42,15 @@ return {
 }
 ```
 
+Using [vim-plug](https://github.com/junegunn/vim-plug)
+
+```viml
+Plug 'fabridamicelli/cronex.nvim'
+
+lua <<EOF
+require("cronex").setup({})
+EOF
+```
 
 ## Usage
 Calling setup makes the explainer available and set explanations when leaving insert mode.  
@@ -102,6 +111,18 @@ require("cronex").setup({
 })
 ```
 
+To embed the above configuration code snippet in a `.vim` file
+(for example in `init.vim`),
+wrap it in `lua << EOF code-snippet EOF`:
+
+```lua
+lua << EOF
+require('cronex').setup{
+  -- ...
+}
+EOF
+```
+
 ### Extractor
 Logic of the default extractor can be found here in `/cronex/cron_from_line.lua`.  
 Default extractor searches for at most 1 expression per line of length 7, 6 or 5 (in that order).