Cardano Updates

Feat: suggest EditorConfig extension for VS Code

Add .vscode/extensions.json to recommend the EditorConfig extension
for VS Code users.

While many modern editors support .editorconfig natively, VS Code
requires an extension. Given VS Code's widespread usage, this extension
should be suggested to ensure all contributors are submitting consistent code formatting, regardless of their editor choice.

CONTRIBUTING.md template used from here:
https://github.com/cardano-community/.github/blob/main/.github/CONTRIBUTING.md

- Include code style guidelines with EditorConfig explanation

Add .editorconfig file to enforce consistent coding standards across
the project.

Template .editorconfig file used from here:
https://github.com/cardano-community/.github/blob/main/.editorconfig

Configures:
- UTF-8 charset encoding
- 2-space indentation for most files
- Unix-style line endings (LF)
- Trim trailing whitespace (except in Markdown)
- Tab indentation for Makefiles
- Final newline requirement

Add .vscode/extensions.json to recommend the EditorConfig extension
for VS Code users.

While many modern editors support .editorconfig natively, VS Code
requires an extension. Given VS Code's widespread usage, this extension
should be suggested to ensure all contributors are submitting consistent code formatting, regardless of their editor choice.

CONTRIBUTING.md template used from here:
https://github.com/cardano-community/.github/blob/main/.github/CONTRIBUTING.md

- Include code style guidelines with EditorConfig explanation

Add .editorconfig file to enforce consistent coding standards across
the project.

Template .editorconfig file used from here:
https://github.com/cardano-community/.github/blob/main/.editorconfig

Configures:
- UTF-8 charset encoding
- 2-space indentation for most files
- Unix-style line endings (LF)
- Trim trailing whitespace (except in Markdown)
- Tab indentation for Makefiles
- Final newline requirement