Use relative repo paths in README

[wnj00524]

No description provided.

[gemini-code-assist]

Code Review

This pull request updates the README.md to replace absolute local file paths with relative paths. The review feedback suggests using the ./ prefix for these relative paths to ensure they are explicitly relative and consistent throughout the document, along with a minor rephrasing for better flow.

[gemini-code-assist]

The phrasing here is a bit redundant. For better flow, you could make the link text more descriptive and integrate it directly into the sentence. Also, prefixing the path with ./ makes it explicitly relative, which is good practice.

Suggested change

	The app ships with a bundled sample file at [sample-network.json](src/MedWNetworkSim.App/Samples/sample-network.json).
	The app ships with [a bundled sample file](./src/MedWNetworkSim.App/Samples/sample-network.json).

[gemini-code-assist]

To make it explicit that these are relative paths and to improve consistency, it's good practice to prefix them with ./.

Suggested change

	- [MainWindow.xaml](src/MedWNetworkSim.App/MainWindow.xaml) defines the main shell: canvas, summary panes, simulation results, and the in-app editor grids.
	- [MainWindowViewModel.cs](src/MedWNetworkSim.App/ViewModels/MainWindowViewModel.cs) is the application coordinator. It loads/saves networks, keeps editor selections in sync, and triggers simulation.
	- [NodeEditorWindow.xaml](src/MedWNetworkSim.App/NodeEditorWindow.xaml) provides the dedicated dropdown-driven node editing workflow.
	- [NetworkFileService.cs](src/MedWNetworkSim.App/Services/NetworkFileService.cs) normalizes and validates JSON data and applies automatic layout.
	- [NetworkSimulationEngine.cs](src/MedWNetworkSim.App/Services/NetworkSimulationEngine.cs) performs routing, capacity competition, bid-cost calculation, and consumer-cost summarization.
	- [MainWindow.xaml](./src/MedWNetworkSim.App/MainWindow.xaml) defines the main shell: canvas, summary panes, simulation results, and the in-app editor grids.
	- [MainWindowViewModel.cs](./src/MedWNetworkSim.App/ViewModels/MainWindowViewModel.cs) is the application coordinator. It loads/saves networks, keeps editor selections in sync, and triggers simulation.
	- [NodeEditorWindow.xaml](./src/MedWNetworkSim.App/NodeEditorWindow.xaml) provides the dedicated dropdown-driven node editing workflow.
	- [NetworkFileService.cs](./src/MedWNetworkSim.App/Services/NetworkFileService.cs) normalizes and validates JSON data and applies automatic layout.
	- [NetworkSimulationEngine.cs](./src/MedWNetworkSim.App/Services/NetworkSimulationEngine.cs) performs routing, capacity competition, bid-cost calculation, and consumer-cost summarization.