Fix type

README.md

@@ -9,7 +9,7 @@ A self-hosted file based task management board that supports Markdown syntax.
 - Write cards as Markdown files;
 - Easy to install with a single Docker image;
 - Light and dark themes synced with operating system settings;
-- Heavy customizable with 3 default color themes ([Adwaita](https://gnome.pages.gitlab.gnome.org/libadwaita/doc/main/named-colors.html), [Nord](https://www.nordtheme.com/) and [Catppuccin](https://github.com/catppuccin/catppuccin));
+- Heavily customizable with 3 default color themes ([Adwaita](https://gnome.pages.gitlab.gnome.org/libadwaita/doc/main/named-colors.html), [Nord](https://www.nordtheme.com/) and [Catppuccin](https://github.com/catppuccin/catppuccin));
 - Support for subpath based reverse-proxy with an environment variable for base path;
 - Can be installed as PWA.