Update syslog.md to correct log type

[mitcherthewitcher]

What does this PR do? What is the motivation?

Update the syslog NDM log collection examples the match the supported custom log configurations described here.

Encountered an issue with a customer Windows Agent where using type:syslog in the log configuration would cause the log listener to initialize and stay stuck in pending state.

I was able to recreate the behavior on my local macOS in our lab account with this configuration:

# in /opt/datadog-agent/etc/conf.d/syslog.d/conf.yaml

logs:
  - type: syslog
    port: 514
    protocol: udp
    source: syslog
    service: test-type-syslog # optional tag
  - type: udp
    port: 514
    protocol: udp
    source: syslog
    service: test-type-udp # optional tag

datadog.yaml

# in /opt/datadog-agent/etc/datadog.yaml
tags:
  - env:lab
api_key:
log_level: info
logs_enabled: true
logs_config:
  use_sourcehost_tag: true

apm_config:
  enabled: true

process_config:
  process_collection:
    enabled: true

site: datadoghq.com

Merge instructions

Merge readiness:

• Ready for merge

Additional notes

Happy to provide a flare or further details if needed, just let me know!

[drichards-87]

Hi @mitcherthewitcher. Thanks for submitting this PR. I've created DOCS-12841 for the Docs Team review. We'll get the PR assigned to someone in the next couple of business days. Thanks!