docs: add conventional commits format to copilot instructions (#133)

Author: jsit

.github/copilot-instructions.md

@@ -1,4 +1,11 @@
-## Required Before Each Commit
+# Copilot Instructions
 
-- Run `npx eslint . --fix` to ensure consistent code formatting with
-    ESLint/Prettier
+- Before each commit, run `npx eslint . --fix` to ensure consistent code
+    formatting with ESLint/Prettier
+
+- Every commit and PR title must conform to Conventional Commits
+    specification. For example:
+    - `feat: add user authentication`
+    - `fix: resolve issue with data fetching`
+    - `docs: update README with setup instructions`
+    - `chore: bump dependencies to latest versions`