Change from "redengine" to "redmail" for import line

docs/tutorials/getting_started.rst

@@ -7,7 +7,7 @@ Install the package from `Pypi <https://pypi.org/project/redmail/>`_:
 
 .. code-block:: console
 
-    pip install redengine
+    pip install redmail
 
 .. _configure:
 
@@ -53,4 +53,4 @@ You can just send emails by calling the method ``send``:
        text="Hi, this is an email."
    )
 
-Next tutorial covers sending emails more thoroughly.
+Next tutorial covers sending emails more thoroughly.