### Describe Your Changes
Marked fluentd in victorialogs roadmap
Added fluentd syslog example setup
### Checklist
The following checks are **mandatory**:
- [ ] My change adheres [VictoriaMetrics contributing
guidelines](https://docs.victoriametrics.com/contributing/).
(cherry picked from commit 05a64a8c14)
### Describe Your Changes
- Use common compose.yaml file for all victorialogs setups to set
version in a single place and override it on demand for each agent and
protocol
- Replaced multiple victorialogs instances in HA setup with single setup
with `deploy.replica` parameter set
- Added fluentd setup
### Checklist
The following checks are **mandatory**:
- [ ] My change adheres [VictoriaMetrics contributing
guidelines](https://docs.victoriametrics.com/contributing/).
(cherry picked from commit e75ae1b274)
