Please add a copyright header with your name and email address.

The scintilla library comes bundled with geany. Is it possible to
unbundle it?

> +    (inputs
> +     `(("gtk2" ,gtk+-2)))

Geany supports gtk3. Could you build with that?

> +    (home-page "https://www.geany.org")
> +    (synopsis "Small and lightweight IDE")

> +    (description "Geany is a small and lightweight Integrated
> +Development Environment.  It was developed to provide a small and fast
> +IDE, which has only a few dependencies from other packages.  Another
> +goal was to be as independent as possible from a special Desktop
> +Environment like KDE or GNOME.

Perhaps rewrite this as:

Geany is a small and fast Integrated Development Environment (IDE) that
only has a few dependencies on other packages and is as independent as
possible from special desktop environments like KDE or GNOME.

> Geany only requires the GTK2 runtime libraries.

I think we should not mention this in the description, especially if we
are building with gtk3.

> +Some basic features of Geany:
> +@itemize
> +@item Syntax highlighting
> +@item Code folding
> +@item Symbol name auto-completion
> +@item Construct completion/snippets
> +@item Auto-closing of XML and HTML tags
> +@item Call tips
> +@item Many supported filetypes including C, Java, PHP, HTML, Python,
> +      Perl, Pascal (full list)

What is (full list) ?

LGTM otherwise, thanks!