Add Dockerfile for building the theme

Dockerfile

@@ -0,0 +1,32 @@
+# This file is part of nginx-fancyindex-flat-theme.
+#
+# nginx-fancyindex-flat-theme is free software: you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or (at your
+# option) any later version.
+#
+# nginx-fancyindex-flat-theme is distributed in the hope that it will be
+# useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+# Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along with
+# this program. If not, see
+#
+#  http://www.gnu.org/licenses/
+#
+#
+# Copyright (C)
+#  2018-2024 Alexander Haase <ahaase@alexhaase.de>
+
+FROM debian
+
+ENV DEBIAN_FRONTEND=noninteractive
+RUN apt update && \
+    apt install -y \
+        make \
+        uglifyjs \
+        node-less \
+        node-less-plugin-clean-css \
+        && \
+    rm -rf /var/lib/apt/lists/*

README.md

@@ -24,10 +24,11 @@ dynamic code.
 
 ## Usage
 
-1. Get the latest resources from [GitHub releases](https://github.com/alehaa/nginx-fancyindex-flat-theme/releases)
-   or build them on your own by running `make` inside this repository and copy
-   these files into any location accessible by *nginx*.
-2. Configure your vhost to use the theme's resources for fancyindex:
+1. Get the latest resources from [GitHub releases][releases], or build them
+   yourself by running `make` inside this repository. Instructions on how to
+   build the resources can be found [below](#build).
+1. Copy these files into any location accessible by *nginx*.
+1. Configure your vhost to use the theme's resources for fancyindex:
     ```
     # Fancyindex
     fancyindex             on;
@@ -43,6 +44,23 @@ dynamic code.
     }
     ```
 
+[releases]: https://github.com/alehaa/nginx-fancyindex-flat-theme/releases
+
+
+## Build
+
+Instead of using pre-built sources, you can build them on a local machine. For
+convenience, a [Dockerfile](Dockerfile) is provided that creates a container
+with all the necessary tools to compile the sources. You can easily build the
+theme using the following commands:
+
+```
+docker build -t fancyindex-flat .
+docker run --rm -it -v ./:/mnt -w /mnt fancyindex-flat make
+```
+
+The compiled sources for the theme will be located in the `build` directory.
+
 
 ## License