mmapstorage: fix spelling in plugin overview
@@ -118,7 +118,7 @@ productive use:
- [camel](camel/) reads and writes a very limited subset of [YAML][]
- [yamlcpp](yamlcpp/) reads and writes data in the [YAML][] format using [yaml-cpp](https://github.com/jbeder/yaml-cpp)
- [yanlr](yanlr/) reads data using a parser generated by [ANTLR](http://www.antlr.org)
-- [mmapstorage](mmapstorage/) uses binary, not portable memory mapped file for high performance storage
+- [mmapstorage](mmapstorage/) uses binary, not portable memory mapped file for a high performance storage
[YAML]: http://www.yaml.org
