Custom themes - delta

# Custom themes

A "theme" in delta is just a collection of settings grouped together in a named feature. One of the available settings is `syntax-theme`: this dictates the colors and styles that are applied to foreground text by the syntax highlighter. Thus the concept of "theme" in delta encompasses not just the foreground syntax-highlighting color theme, but also background colors, decorations such as boxes and under/overlines, etc.

The delta git repo contains a collection of themes created by users. These focus on the visual appearance: colors etc. If you want features like `side-by-side` or `navigate`, you would set that yourself, after selecting the color theme. To use the delta themes, clone the delta repo (or download the raw `themes.gitconfig` file) and add the following entry in your gitconfig:

    [include]
        path = /PATH/TO/delta/themes.gitconfig

Then, add your chosen color theme to your features list, e.g.

    [delta]
        features = collared-trogon
        side-by-side = true
        ...

Note that this terminology differs from bat: bat does not apply background colors, and uses the term "theme" to refer to what delta calls `syntax-theme`. Delta does not have a setting named "theme": a theme is a "feature", so one uses `features` to select a theme.