doc: add ./NEWS as "Release notes" section

NEWS

+Knot Resolver 2.x.0 (2018-0M-DD)
+================================
+
 Incompatible changes
 --------------------
 - cache: fail lua cache operations if it isn't open (!639)

doc/NEWS.rst

+*************
+Release notes
+*************
+
+.. include:: ../NEWS
+

doc/conf.py

@@ -23,7 +23,7 @@ master_doc = 'index'
 
 # General information about the project.
 project = u'Knot DNS Resolver'
-copyright = u'2014-2017 CZ.NIC labs'
+copyright = u'2014-2018 CZ.NIC labs'
 version = { k[0][0]: k[0][1] for k in filter(None, [re.findall(r'(MAJOR|MINOR|PATCH) := ([0-9]+)',line) for line in open('../config.mk')])}
 version = '%s.%s.%s' % (version['MAJOR'], version['MINOR'], version['PATCH'])
 release = version

doc/index.rst

@@ -14,6 +14,7 @@ and it provides a state-machine like API for extensions.
    build
    lib
    modules_api
+   NEWS
 
 
 Indices and tables