Reword and fix formatting of mvn plugin README

plugins/mvn/README.md

-## The mvn Plugin
+## Introduction
 
-The [mvn](https://github.com/robbyrussell/oh-my-zsh/tree/master/plugins/mvn) plugin provides many [aliases](#Aliases).
+The [mvn plugin](https://github.com/robbyrussell/oh-my-zsh/tree/master/plugins/mvn) provides many
+[useful aliases](#aliases) as well as completion for the `mvn` command.
 
-Enable it by adding _mvn_ to the [_plugins array_](https://github.com/robbyrussell/oh-my-zsh/blob/master/templates/zshrc.zsh-template#L48) before sourcing OMZ (see [Plugins](https://github.com/robbyrussell/oh-my-zsh/wiki/Plugins)).
+Enable it by adding `mvn` to the plugins array in your zshrc file:
+```zsh
+plugins=(... mvn)
+```
 
 ## Aliases
 
-| Alias                | Command                                                                                                                                   |
-|:---------------------|:------------------------------------------------------------------------------------------------------------------------------------------|
-|mvncie|mvn clean install eclipse:eclipse|
-|mvnci|mvn clean install|
-|mvncist|mvn clean install -DskipTests|
-|mvne|mvn eclipse:eclipse|
-|mvnd|mvn deploy|
-|mvnp|mvn package|
-|mvnc|mvn clean|
-|mvncom|mvn compile|
-|mvnct|mvn clean test|
-|mvnt|mvn test|
-|mvnag|mvn archetype:generate|
-|mvn-updates|mvn versions:display-dependency-updates|
-|mvntc7|mvn tomcat7:run|
-|mvnjetty|mvn jetty:run|
-|mvndt|mvn dependency:tree|
-|mvns|mvn site|
-|mvnsrc|mvn dependency:sources|
-|mvndocs|mvn dependency:resolve -Dclassifier=javadoc|
+| Alias                | Command                                         |
+|:---------------------|:------------------------------------------------|
+| `mvncie`             | `mvn clean install eclipse:eclipse`             |
+| `mvnci`              | `mvn clean install`                             |
+| `mvncist`            | `mvn clean install -DskipTests`                 |
+| `mvne`               | `mvn eclipse:eclipse`                           |
+| `mvnd`               | `mvn deploy`                                    |
+| `mvnp`               | `mvn package`                                   |
+| `mvnc`               | `mvn clean`                                     |
+| `mvncom`             | `mvn compile`                                   |
+| `mvnct`              | `mvn clean test`                                |
+| `mvnt`               | `mvn test`                                      |
+| `mvnag`              | `mvn archetype:generate`                        |
+| `mvn-updates`        | `mvn versions:display-dependency-updates`       |
+| `mvntc7`             | `mvn tomcat7:run`                               |
+| `mvnjetty`           | `mvn jetty:run`                                 |
+| `mvndt`              | `mvn dependency:tree`                           |
+| `mvns`               | `mvn site`                                      |
+| `mvnsrc`             | `mvn dependency:sources`                        |
+| `mvndocs`            | `mvn dependency:resolve -Dclassifier=javadoc`   |