docs(copilot): add commit message guidelines

Added guidelines for writing commit messages following the conventional commits format to ensure consistency and clarity in the repository.

- Included instructions on the format: `<type>(<scope>): <description>`
- Provided examples for both feature and fix commit messages
- Emphasized the importance of present tense and detailed descriptions

Author: JaCraig

.github/copilot-instructions.md

@@ -0,0 +1,32 @@
+# Copilot Instructions
+
+## Commit Messages
+
+- Use [conventional commits](https://www.conventionalcommits.org/en/v1.0.0/) message format. Format: `<type>(<scope>): <description>`
+- Include scope in the title.
+- The subject should be in present tense describing the overall changes as a completed action.
+- The next paragraph should be an overall description of the changes.
+- Subsequent lines should be a bulleted list of the changes.
+
+Example 1:
+
+```
+feat(services): add new user registration endpoint
+
+Added a new API endpoint for user registration that accepts email and password, creates a new user in the database, and returns a JWT token.
+
+- Created `RegisterUserCommand` and corresponding handler in `GreenField.Services`
+- Added `POST /api/register` endpoint in `API/Controllers/AuthController.cs`
+- Updated database schema with new `Users` table via Inflatable mapping
+```
+
+Example 2:
+
+```
+fix(frontend): resolve issue with theme variable loading
+
+Fixed a bug where theme CSS variables were not loading correctly on initial page load, causing the default theme to be applied instead of the user's selected theme.
+
+- Updated `ThemeService` to ensure CSS variables are applied before the first render
+- Added unit tests for `ThemeService` to verify correct variable application
+```