Add Bundler config and .gitignore for local gem installation (#59)

- Add .bundle/config to set local vendor/bundle path by default
- Add .gitignore to exclude vendor/bundle/ and other common files
- This ensures 'bundle install' works without sudo on all systems
- Gems install to project-local directory instead of system location

Benefits:
- No permission issues when running bundle install
- Each developer gets isolated gem environment
- Consistent setup across all development machines
- Avoids conflicts with system Ruby gems

Co-authored-by: factory-droid[bot] <138933559+factory-droid[bot]@users.noreply.github.com>

Author: chorrell

.bundle/config

@@ -0,0 +1,2 @@
+---
+BUNDLE_PATH: "vendor/bundle"

.gitignore

@@ -0,0 +1,15 @@
+# Bundler
+vendor/bundle/
+.bundle/config.local
+
+# macOS
+.DS_Store
+
+# Editor files
+.vscode/
+*.swp
+*.swo
+*~
+
+# Test coverage
+coverage/