Create README.md

README.md

+## Poly light GRUB theme
+
+![](https://i.imgur.com/XitFbtv.gif)
+
+### Installation
+
+1. Get theme archive: `wget https://github.com/shvchk/poly-light/archive/master.zip`
+2. Unpack theme: `unzip master.zip`
+3. Remove theme archive: `rm master.zip`
+4. Create GRUB themes directory: `sudo mkdir -p /boot/grub/themes`
+5. Move theme to GRUB themes directory: `sudo mv poly-light-master /boot/grub/themes/poly-light`
+6. Set `GRUB_THEME=/boot/grub/themes/poly-light/theme.txt` in GRUB config: `sudo nano /etc/default/grub`
+7. Update GRUB: `sudo update-grub`