minor formatting fix to ensure_str documentation (#273)
Small update to the `ensure_str` function's documentation formatting to
match `ensure_binary` and `ensure_text`'s formatting.
diff --git a/documentation/index.rst b/documentation/index.rst
index d0c605d..c4d1d83 100644
--- a/documentation/index.rst
+++ b/documentation/index.rst
@@ -444,7 +444,7 @@
.. function:: ensure_str(s, encoding='utf-8', errors='strict')
- Coerce *s* to ``str``. ``encoding``, ``errors`` are the same
+ Coerce *s* to ``str``. *encoding*, *errors* are the same
:meth:`py3:str.encode`
