Drop gradle

.gitignore

@@ -1,7 +1,7 @@
-.gradle/
-gradle.properties
-source/_build/*
-.idea/*
-.vscode/*
-build/*
+# Folders
+source/_build
+.idea/
+.vscode/
+build/
+
 *.iml

README.md

@@ -0,0 +1,100 @@
+
+# 3D City Database User Manual
+
+The 3DCityDB User Manual is built and hosted on [ReadTheDocs.org](https://readthedocs.org).
+Please use the link below to find the online version of this documentation.
+
+<br/>
+<p align="center">:arrow_right: https://3dcitydb-docs.readthedocs.io/en/latest/ :arrow_left:</p>
+<br/>
+
+![cover_image](source/media/cover_image.png)
+
+The images on the cover page were provided by:
+
+- Chair of Photogrammetry and Remote Sensing & Chair of Cartography, Technische Universität München
+
+- Geobasisdaten: © Stadtvermessung Frankfurt am Main
+
+- IDAC Ltd, UK.
+
+- Virtual City Systems, Berlin, Germany
+
+- Chair of Geoinformatics, Technische Universität München. Image created based on master thesis work of Matthias Körner, jointly supervised with HTW Dresden
+
+- 3D City Model of Berlin © Berlin Partner GmbH
+
+- M.O.S.S. Computer Grafik Systeme GmbH, Taufkirchen, Germany
+
+## How to build this documentation
+
+### Build with Docker
+
+To avoid setting up the build environment, it is recommended to use [Docker](https://docs.docker.com/get-docker/)
+and [this Docker image](https://github.com/BWibo/sphinx-rtd-docker) to build this documentation.
+
+#### Build process
+
+1. Clone this repo and navigate to the repo folder:
+
+   ```bash
+   git clone https://github.com/3dcitydb/3dcitydb-docs.git
+   cd 3dcitydb-docs
+   ```
+
+2. Mount the current directory to the images `/docs` folder and build the HTML version:
+
+    ```bash
+    docker run --rm \
+      -v $PWD:/docs \
+    bwibo/sphinx-rtd make html
+    ```
+
+3. The build files are in `build/html`.
+
+### Build in a local Python environment
+
+To build this documentation following tools are required:
+
+- Python 3.6+: <https://www.python.org/>
+- Sphinx: <https://www.sphinx-doc.org/en/master/usage/installation.html>
+- Sphinx ReadTheDocs Theme: <https://sphinx-rtd-theme.readthedocs.io/en/stable/>
+- Sphinx copybutton: <https://sphinx-copybutton.readthedocs.io/en/latest/>
+
+Run this to install all dependencies in an existing Python environment using
+[pip](https://packaging.python.org/tutorials/installing-packages/https://packaging.python.org/tutorials/installing-packages/):
+
+```python
+pip install -U sphinx
+pip install -U -r source/requirements.txt
+```
+
+#### Build process
+
+1. Clone this repo and navigate to the repo folder:
+
+   ```bash
+   git clone https://github.com/3dcitydb/3dcitydb-docs.git
+   cd 3dcitydb-docs
+   ```
+
+2. Build the HTML version of the documentation:
+
+   - Linux:
+
+      ```bash
+      make html
+      ```
+
+   - Windows:
+
+      ```cmd
+      make.bat html
+      ```
+
+3. The build files are in `build/html`.
+
+## Documentations of previous versions
+
+Documentations of previous versions are available as PDF here:
+<https://www.3dcitydb.org/3dcitydb/documentation/>