improve readme

README.rst

@@ -3,7 +3,8 @@ Introduction
 
 .. inclusion-marker-do-not-remove
 
-KML is an XML geospatial data format and an OGC_ standard that deserves a canonical python implementation.
+KML is an XML geospatial data format and an OGC_ standard that deserves a canonical
+python implementation.
 
 Fastkml is a library to read, write and manipulate KML files. It aims to keep
 it simple and fast (using lxml_ if available). Fast refers to the time you
@@ -19,9 +20,12 @@ For more details about the KML Specification, check out the `KML Reference
 <https://developers.google.com/kml/documentation/kmlreference>`_ on the Google
 developers site.
 
-Geometries are handled as pygeoif_ objects.
+Geometries are handled as pygeoif_ objects, which are compatible with any geometry that
+implements the ``__geo_interface__`` protocol, such as shapely_.
 
-Fastkml is continually tested
+Fastkml is tested on `CPython <https://python.org>`_ and
+`PyPy <https://www.pypy.org/>`_, but it should work on alternative
+Python implementations (that implement the language specification *>=3.8*) as well.
 
 |test| |hypothesis| |cov| |black| |mypy| |commit|
 
@@ -49,7 +53,7 @@ Fastkml is continually tested
    :target: https://github.com/pre-commit/pre-commit
    :alt: pre-commit
 
-Is Maintained and documented:
+Is maintained and documented:
 
 |pypi| |conda-forge| |status| |license| |doc| |stats| |pyversion| |pyimpl| |dependencies| |downloads|
 
@@ -134,3 +138,4 @@ Please submit a PR with the features you'd like to see implemented.
 .. _lxml: https://pypi.python.org/pypi/lxml
 .. _arrow: https://pypi.python.org/pypi/arrow
 .. _OGC: https://www.ogc.org/standard/kml/
+.. _shapely: https://shapely.readthedocs.io/