move parts of games.ipynb into synthesis.ipynb

* tests/python/synthesis.ipynb: New file, with bits removed from...
* tests/python/games.ipynb: ... here.
* tests/Makefile.am: Add synthesis.ipynb.
* NEWS, doc/org/tut.org: Mention the new notebook.

NEWS

@@ -289,6 +289,7 @@ New in spot 2.9.8.dev (not yet released)
     https://spot.lrde.epita.fr/tut40.html for examples.
 
   - Bindings for functions related to syntethis and aig-circuits.
+    See https://spot.lrde.epita.fr/ipynb/synthesis.html
 
   - spot::twa::prop_set was previously abstent from the Python
     bindings, making it impossible to call make_twa_graph() for copying

doc/org/tut.org

@@ -74,6 +74,7 @@ real notebooks instead.
 - [[https://spot.lrde.epita.fr/ipynb/parity.html][=parity.ipynb=]] documents algorithms for manipulating parity automata
   in Python
 - [[https://spot.lrde.epita.fr/ipynb/games.html][=games.ipynb=]] illustrates support for games
+- [[https://spot.lrde.epita.fr/ipynb/synthesis.html][=synthesis.ipynb=]] illustrates support for game-based LTL reactive synthesis
 - [[https://spot.lrde.epita.fr/ipynb/product.html][=product.ipynb=]] shows how to re-implement the product of two automata
   in Python
 - [[https://spot.lrde.epita.fr/ipynb/randltl.html][=randltl.ipynb=]] demonstrates a Python-version of [[file:randltl.org][=randltl=]]

tests/Makefile.am

@@ -370,6 +370,7 @@ TESTS_ipython = \
   python/randltl.ipynb \
   python/satmin.ipynb \
   python/stutter-inv.ipynb \
+  python/synthesis.ipynb \
   python/testingaut.ipynb \
   python/twagraph-internals.ipynb \
   python/word.ipynb \