Add package finding and packing of *.tx files to setup.cfg

Author: igordejanovic

textxdev/scaffold/template/setup.cfg.jinja

@@ -27,7 +27,7 @@ classifiers =
     Operating System :: OS Independent
 
 [options]
-packages = {{package}}
+packages = find:
 zip_safe = False
 install_requires =
     textX
@@ -46,6 +46,11 @@ test =
     coveralls
     pytest
 
+{% if type=="lang" %}
+[options.package_data]
+    {{package}} = *.tx
+{% endif %}
+
 [options.entry_points]
 {% if type=="lang" %}
 textx_languages =