Issue:
doc: documentation for payment method routes

## Type of Change
<!-- Put an `x` in the boxes that apply -->
- [x] Enhancement

## Description
<!-- Describe your changes in detail -->
Written documentation for Payment Method routes


## Motivation and Context
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Why is this change required? What problem does it solve?
If it fixes an open issue, please link to the issue here.

If you don't have an issue, we'd recommend starting with one first so the PR
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N/A

## How did you test it?
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Manual

## Checklist
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- [x] I formatted the code `cargo +nightly fmt --all`
- [x] I addressed lints thrown by `cargo clippy`
- [x] I reviewed submitted code


Resolution:
<think>
PR Context:
- Title: build(deps): use utoipa crate upstream URL as git dependency
- Merged: 2023-01-16T09:12:32Z
- Files changed: 5 files
- Commits: 4 commits

Implementation approach:
## Type of Change
<!-- Put an `x` in the boxes that apply -->

- [ ] Bugfix
- [ ] New feature
- [ ] Enhancement
- [ ] Refactoring
- [x] Dependency updates

## Description
<!-- Describe your changes in detail -->
This PR updates the repository URL for the `utoipa` crate to use the upstream repository URL instead of my fork.

## Motivation and Context
<!--
Why is this change required? What problem does it solve?
If it fixes an open issue, please link to the issue here.

If you do
</think>

To implement this, you'll need to modify:


**Detailed Implementation:**


**Commit 1:** build(deps): use utoipa crate upstream URL as git dependency (#378)
Files to modify:


**crates/api_models/src/admin.rs**
  Modify existing code