docs(analytics): Instructions to set up `currency_conversion` (third party dependency API)

## Requirements
After the changes by [this](#6418) PR, we need to update the documentation for `analytics` crate setup process.

## Reason
Due to the third party dependency on `currency_conversion` crate, we need to ensure the proper setup of this service as well.
<think>
PR Context:
- Title: docs(analytics): add setup instructions for currency_conversion service
- Merged: 2024-11-13T09:54:17Z
- Files changed: 1 files
- Commits: 1 commits

Implementation approach:
## Type of Change
<!-- Put an `x` in the boxes that apply -->

- [ ] Bugfix
- [ ] New feature
- [ ] Enhancement
- [ ] Refactoring
- [ ] Dependency updates
- [x] Documentation
- [ ] CI/CD

## Description
<!-- Describe your changes in detail -->
Now that `analytics` depends on `currency_conversion` crate after this [PR](#6418), we need to include instructions in `analytics` documentation to set up this service.
## Fixes #6513 
### Additional Changes

- [ ] This PR modifies the API
</think>

To implement this, you'll need to modify:


(No detailed commit information available)
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