trim obsolete sentence re: i18n extension
This sentence seems like a leftover from when i18n was the only extension available, eh?
diff --git a/docs/extensions.rst b/docs/extensions.rst
index 2d9493f..0825fd4 100644
--- a/docs/extensions.rst
+++ b/docs/extensions.rst
@@ -27,10 +27,9 @@
**Import name:** `jinja2.ext.i18n`
-Jinja2 currently comes with one extension, the i18n extension. It can be
-used in combination with `gettext`_ or `babel`_. If the i18n extension is
-enabled Jinja2 provides a `trans` statement that marks the wrapped string as
-translatable and calls `gettext`.
+The i18n extension can be used in combination with `gettext`_ or `babel`_. If
+the i18n extension is enabled Jinja2 provides a `trans` statement that marks
+the wrapped string as translatable and calls `gettext`.
After enabling, dummy `_` function that forwards calls to `gettext` is added
to the environment globals. An internationalized application then has to