Add Splunk configuration templates to Wazuh packages

[AlexRuiz7]

Description

We currently host the Splunk configuration files our app requires in this repository. We have been asked to migrate these configuration files to the Wazuh packages domain, as done for our Kibana app:
https://packages.wazuh.com/4.x/filebeat/

The files to migrate are those that are inside the setup/ folder of this repository.

[AlexRuiz7]

Comparison and required changes

Command for Elastic

curl -so /etc/filebeat/filebeat.yml https://packages.wazuh.com/4.3/tpl/wazuh/filebeat/filebeat.yml

Current commands for Splunk

# Indexer
curl -so /opt/splunk/etc/system/local/indexes.conf https://raw.githubusercontent.com/wazuh/wazuh-splunk/v4.3.8-8.2.6/setup/indexer/indexes.conf
curl -so /opt/splunk/etc/system/local/inputs.conf https://raw.githubusercontent.com/wazuh/wazuh-splunk/v4.3.8-8.2.6/setup/indexer/inputs.conf

# Forwarder
curl -so /opt/splunkforwarder/etc/system/local/props.conf https://raw.githubusercontent.com/wazuh/wazuh-splunk/v4.3.8-8.2.6/setup/forwarder/props.conf
curl -so /opt/splunkforwarder/etc/system/local/inputs.conf https://raw.githubusercontent.com/wazuh/wazuh-splunk/v4.3.8-8.2.6/setup/forwarder/inputs.conf

Desired commands for Splunk

# Indexer
curl -so /opt/splunk/etc/system/local/indexes.conf https://packages.wazuh.com/4.3/tpl/wazuh/splunk/indexer/indexes.conf
curl -so /opt/splunk/etc/system/local/inputs.conf https://packages.wazuh.com/4.3/tpl/wazuh/splunk/indexer/inputs.conf

# Forwarder
curl -so /opt/splunkforwarder/etc/system/local/props.conf https://packages.wazuh.com/4.3/tpl/wazuh/splunk/forwarder/props.conf
curl -so /opt/splunkforwarder/etc/system/local/inputs.conf https://packages.wazuh.com/4.3/tpl/wazuh/splunk/forwarder/inputs.conf

Affected documentation pages:

• Install Splunk in an all-in-one architecture
• Install a minimal Splunk distributed architecture