add code to generate member map

README.md

@@ -1,3 +1,35 @@
-# member-map
+# Map of Germany with highlighted WTF member locations
 
-Generate a map of Germany with highlighted WTF member locations.
+## Docker Usage
+
+Download the Germany PLZ dataset in the GeoJSON format from
+https://opendata-esri-de.opendata.arcgis.com/datasets/5b203df4357844c8a6715d7d411a8341_0
+and place the file in the root of this repository.
+
+Place a JSON file containing a list of PLZ prefixes as `wtf_member_plz_prefixes.json` in
+the root of this repository.
+The file contents should look like `["121", "635"]` for PLZ data that is anonymized to
+the first three digits.
+
+The following will build a Docker image and render the map with the default
+configuration for the WTF member PLZ prefix data:
+```
+docker build -t wtf-map .
+docker run wtf-map > map.png
+```
+
+Note, the build command already renders the map and thus can take a moment.
+The run command just outputs the already rendered image to be piped into any target
+file on the host system.
+
+## Script Usage
+
+In case you'd like custom colors or use different data, you are encouraged to use the
+script explicity.
+To get all relevant requirements, you can `pip install -r requirements.txt`, but note,
+you might need to install BLAS and GEOS libraries on your system.
+
+The following will tell you all about what you can adjust for a custom visualization:
+```
+python main.py --help
+```