highlight code sections

README.md

@@ -17,7 +17,7 @@ version is v0.10+
 `Packer` allows the use of a complete URL, which can then be renamed for
 ease of use.
 
-```
+```lua
 use {
     'https://git.folkert-kevelam.nl/folkert/Neovim-SpecSwitcher.git',
     as = 'SpecSwitcher'
@@ -38,7 +38,7 @@ for the switch: `<leader>n`. If you want a different shortcut, the option
 
 ### Basic Setup
 
-```
+```lua
 require('SpecSwitcher').setup({
     descend_dirs={
         "include",