Fix a typo in the docs.

docsite/latest/rst/playbooks.rst

@@ -36,7 +36,7 @@ Playbook Language Example
 Playbooks are expressed in YAML format and have a minimum of syntax.
 Each playbook is composed of one or more 'plays' in a list.
 
-The goal of a play is map a group of hosts to some well defined roles, represented by
+The goal of a play is to map a group of hosts to some well defined roles, represented by
 things ansible called tasks.  At the basic level, a task is nothing more than a call
 to an ansible module, which you should have learned about in earlier chapters.