### Describe Your Changes
Updated user management guide with new cloud content
This PR should be merged after the cloud PR
### Checklist
The following checks are **mandatory**:
- [x] My change adheres [VictoriaMetrics contributing
guidelines](https://docs.victoriametrics.com/contributing/).
### Describe Your Changes
* `sort` param is unused by the current website engine, and was present only for compatibility
with previous website engine. It is time to remove it as it makes no effect
* re-structure guides content into folders to simplify assets management
### Checklist
The following checks are **mandatory**:
- [ ] My change adheres [VictoriaMetrics contributing
guidelines](https://docs.victoriametrics.com/contributing/).
The changes are based on SEO report and supposed to improve
ranking and indexation by search engines by using prompt and unique titles
and by updating unreachable links.
It also updates links to have a simplified form and replaces relative links with absolute links
according to https://docs.victoriametrics.com/#documentation
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Co-authored-by: Roman Khavronenko <roman@victoriametrics.com>
### Describe Your Changes
These changes were made as part of the title transition from Managed
VictoriaMetrics to VictoriaMetrics Cloud
### Checklist
The following checks are **mandatory**:
- [x] My change adheres [VictoriaMetrics contributing
guidelines](https://docs.victoriametrics.com/contributing/).
