* cross-link related doc chapters and guides about otel
* mention different URL format for cluster version of VM
Signed-off-by: hagen1778 <roman@victoriametrics.com>
### Describe Your Changes
This pull request fixes incorrect URLs in two places:
1. In the OTel guide, which has been corrected in
https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6880, but one
incorrect URL is still missing.
2. In the URL example, the cache reset endpoint for vmselect / Cluster
version is `/internal/resetRollupResultCache`, but it is mistakenly
noted as `/select/internal/resetRollupResultCache`, which misguides the
user. (introduced in #4468)
### 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/).