Re-arrange navbar to match new layout of examples page

Author: mborland

doc/modules/ROOT/nav.adoc

@@ -9,8 +9,8 @@
 ** xref:examples.adoc#examples_finance[Financial Applications]
 ** xref:examples.adoc#examples_boost_math[Boost.Math Integration]
 ** xref:examples.adoc#examples_format[Formatting]
+*** xref:examples.adoc#examples_fmt_format[pass:[{fmt}]]
 *** xref:examples.adoc#examples_std_format[`<format>`]
-*** xref:examples.adoc#examples_fmt_format[+{fmt}+]
 ** xref:examples.adoc#examples_print[`<print>`]
 * xref:api_reference.adoc[]
 ** xref:api_reference.adoc#api_ref_types[Types]