doc: document how to use tinted-delta

Author: bezhermoso

USAGE.md

@@ -17,6 +17,7 @@ For more general usage, look at the [Usage section] in [README.md].
 - [qutebrowser](#qutebrowser)
 - [rofi](#rofi)
 - [dunst](#dunst)
+- [delta](#delta)
 
 ## Shell completions
 
@@ -502,6 +503,39 @@ However, limited testing has shown `dunst` will not complain if its configuratio
 hook = "cat ~/.config/dunst/dunstrc.local %f > ~/.config/dunst/dunstrc && systemctl --user restart dunst"
 ```
 
+## Delta
+
+Add the following to `~/.config/tinted-theming/tinty/config.toml`:
+
+```toml
+[[items]]
+path = "https://github.com/tinted-theming/tinted-delta"
+name = "delta"
+themes-dir = "configs"
+hook = "cp -f %f ~/.config/tinted-theming/delta.gitconfig"
+supported-systems = ["base16", "base24"]
+```
+
+Configure [delta] as your Git pager and/or difftool under the name `delta`, like this:
+
+```gitconfig
+[core]
+	pager = delta
+
+[interactive]
+	diffFilter = delta --color-only
+
+# Delta configuration not related to theming:
+[delta]
+	navigate = true
+	line-numbers = true
+	hyperlinks = true
+	tabs = 4
+
+# Include the config file generated by the tinty hook, which contains theme-related configuration:
+[include]
+	path = ~/.config/tinted-theming/delta.gitconfig
+```
 [Usage section]: https://github.com/tinted-theming/tinty?tab=readme-ov-file#usage
 [README.md]: https://github.com/tinted-theming/tinty/blob/main/README.md
 [bat]: https://github.com/sharkdp/bat
@@ -515,3 +549,4 @@ hook = "cat ~/.config/dunst/dunstrc.local %f > ~/.config/dunst/dunstrc && system
 [README CLI section]: README.md#cli
 [contrib/completion]: contrib/completion
 [base16-qutebrowser]: https://github.com/tinted-theming/base16-qutebrowser
+[delta]: https://github.com/dandavison/delta