add stack to tutorial docs (#1177)

* add stack to tutorial docs

* adjusted stack install wording

doc/tutorial/index.rst

@@ -6,8 +6,11 @@ This is an introductory tutorial to **servant**. Whilst browsing is fine, it mak
 Any comments, issues or feedback about the tutorial can be submitted
 to `servant's issue tracker <http://github.com/haskell-servant/servant/issues>`_.
 
-In fact, the whole tutorial is a `cabal <https://cabal.readthedocs.io/en/latest/>`_
+cabal-install
-project and can be built and played with locally as follows:
+--------
+
+The whole tutorial is a `cabal <https://cabal.readthedocs.io/en/latest/>`_
+project and can be built locally as follows:
 
 .. code-block:: bash
 
@@ -18,6 +21,20 @@ project and can be built and played with locally as follows:
    # load in ghci to play with it
    $ cabal new-repl tutorial
 
+stack
+--------
+
+The servant `stack <https://docs.haskellstack.org/en/stable/README/>`_ template includes the working tutorial. To initialize this template, run:
+
+.. code-block:: bash
+
+   $ stack new myproj servant
+   $ cd myproj
+   # build
+   $ stack build
+   # start server
+   $ stack exec myproj-exe
+
 The code can be found in the `*.lhs` files under `doc/tutorial/` in the
 repository. Feel free to edit it while you're reading this documentation and
 see the effect of your changes.