fix(openapi): Standardise API naming scheme for V2

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

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

## Description
<!-- Describe your changes in detail -->
Use kebab-case for all API endpoints in V2

### Additional Changes

- [x] This PR modifies the API contract
- [ ] This PR modifies the database schema
- [ ] This PR modifies application configuration/environment variables

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2. `crates/router/src/configs`
3. `loadtest/config`
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## Motivation and Context
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## How did you test it?
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This is mostly a documentation PR, doesn't require any additional test cases.

Verified that existing cypress tests are passing

## Checklist
<!-- Put an `x` in the boxes that apply -->

- [x] I formatted the code `cargo +nightly fmt --all`
- [x] I addressed lints thrown by `cargo clippy`
- [x] I reviewed the submitted code
- [ ] I added unit tests for my changes where possible

<think>
PR Context:
- Title: fix(openapi): Revert Standardise API naming scheme for V2 Dashboard Changes
- Merged: 2024-12-02T09:29:35Z
- Files changed: 1 files
- Commits: 1 commits

Implementation approach:
Reverts part of juspay/hyperswitch#6510

This PR also changed the dashboard related APIs, which doesn't come under the V2 changes that team is doing. As this is not a backwards compatible change, dashboard is breaking. Revert the dashboard API related changes.
</think>

To implement this, you'll need to modify:


**Detailed Implementation:**


**Commit 1:** fix(openapi): Revert Standardise API naming scheme for V2 Dashboard Changes (#6712)
Files to modify:


**crates/router/src/routes/app.rs**
  Modify existing code
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