<commit_before>The idea of this plugin is to create a worker that can:
* monitor remote machine
* execute bash
* grep logs

#Monitor remote machine

```xml
<benchmark xmlns="urn:radargun:benchmark:3.0">
    <main bindAddress="${main.address:127.0.0.1}" port="${main.port:2103}"/>
    <clusters>
        <cluster size="3">
            <group name="echo" size="2" />
            <group name="client" size="1" />
        </cluster>
    </clusters>
    <configurations>

        <config name="my-example">
            <setup group="echo" plugin="echo">
                <echo xmlns="urn:radargun:plugins:${env.PLUGINNAME}:3.0" />
            </setup>
            <setup group="client" plugin="${env.PLUGINNAME}">
                <hotrod .....
            </setup>
        </config>

    </configurations>
    <init/>
    <rg:scenario ....

        <service-start />
        <remote-monitor-start jmx-service-url="service:jmx:rmi:///jndi/rmi://127.0.0.1:9999/jmxrmi" groups="echo" workers="0"/>
        <remote-monitor-start jmx-service-url="service:jmx:rmi:///jndi/rmi://127.0.0.1:9998/jmxrmi" groups="echo" workers="1"/>
        <monitor-start groups="client"/>

        <l:basic-operations-test ...

        <jvm-monitor-stop />
        <service-stop />
```<commit_msg>Fix doc for echo plugin<commit_after>The idea of this plugin is to create a worker that can:
* monitor remote machine
* execute bash
* grep logs

#Monitor remote machine

```xml
<benchmark xmlns="urn:radargun:benchmark:3.0">
    <main bindAddress="${main.address:127.0.0.1}" port="${main.port:2103}"/>
    <clusters>
        <cluster size="3">
            <group name="echo" size="2" />
            <group name="client" size="1" />
        </cluster>
    </clusters>
    <configurations>

        <config name="my-example">
            <setup group="echo" plugin="echo">
                <echo xmlns="urn:radargun:plugins:echo:3.0" />
            </setup>
            <setup group="client" plugin="${env.PLUGINNAME}">
                <hotrod .....
            </setup>
        </config>

    </configurations>
    <init/>
    <rg:scenario ....

        <service-start />
        <remote-monitor-start jmx-service-url="service:jmx:rmi:///jndi/rmi://127.0.0.1:9998/jmxrmi" groups="echo" workers="0"/>
        <remote-monitor-start jmx-service-url="service:jmx:rmi:///jndi/rmi://127.0.0.1:9999/jmxrmi" groups="echo" workers="1"/>
        <monitor-start groups="client"/>

        <l:basic-operations-test ...

        <monitor-stop />
        <service-stop />
```
{'fraction_non_alphanumeric': 0.18415841584158416, 'fraction_numerical': 0.03089108910891089, 'mean_word_length': 2.2762645914396886, 'pattern_counts': {'":': 0, '<': 57, '<?xml version=': 0, '>': 51, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 6}, 'pii_count': 6, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
{'dir': 'git-commits-cleaned', 'id': '4000999', 'n_tokens_mistral': 876, 'n_tokens_neox': 821, 'n_words': 146}