### Describe Your Changes
Small improvements to a QuickStart guide of `vmanomaly`
### Checklist
The following checks are **mandatory**:
- [x] My change adheres [VictoriaMetrics contributing
guidelines](https://docs.victoriametrics.com/contributing/).
- Fixed config example in QuickStart vmanomaly docs for 1.13 version
compatibility
- [x] My change adheres [VictoriaMetrics contributing
guidelines](https://docs.victoriametrics.com/contributing/).
(cherry picked from commit 4b77778ff5)
* docs/vmanomaly: v1.12.0 & link updates
* add autotuned description to model section
* - update refs of vmanomaly on enterprise and vmalert pages
- add diagrams for model types
- update self-monitoring section
* - fix typos
- remove .index.html from links