Add wradlib to ecosystem in docs (pydata#5915)

Author: kmuehlbauer

doc/ecosystem.rst

@@ -37,6 +37,7 @@ Geosciences
 - `Spyfit <https://spyfit.readthedocs.io/en/master/>`_: FTIR spectroscopy of the atmosphere
 - `windspharm <https://ajdawson.github.io/windspharm/index.html>`_: Spherical
   harmonic wind analysis in Python.
+- `wradlib <https://wradlib.org/>`_: An Open Source Library for Weather Radar Data Processing.
 - `wrf-python <https://wrf-python.readthedocs.io/>`_: A collection of diagnostic and interpolation routines for use with output of the Weather Research and Forecasting (WRF-ARW) Model.
 - `xarray-simlab <https://xarray-simlab.readthedocs.io>`_: xarray extension for computer model simulations.
 - `xarray-spatial <https://makepath.github.io/xarray-spatial>`_: Numba-accelerated raster-based spatial processing tools (NDVI, curvature, zonal-statistics, proximity, hillshading, viewshed, etc.)