Update .gitattributes and .gitignore for improved package and repo management (#18)

* exclude non-essential files and directories from package distribution

- Added entries to .gitattributes to exclude:
  - /examples: Example files
  - /tests: Test files
  - .gitattributes: Git-specific configuration
  - .github: GitHub-related files
  - .gitignore: Git ignore rules
  - CHANGELOG-*: Changelog files
  - CODE_OF_CONDUCT.md: Code of conduct document
  - CONTRIBUTING.md: Contribution guidelines
  - UPGRADING.md: Upgrade instructions
  - RELEASE.md: Release notes

* update .gitignore to include additional files and directories

- Added .idea/ and .idea: Exclude JetBrains IDE configuration directories
- Added composer.lock: Exclude Composer lock file (if needed)
- Added .fleet: Exclude Fleet IDE configuration (if applicable)
- Added .vscode: Exclude Visual Studio Code configuration directory

---------

Co-authored-by: Jamie Barton <jamie@notrab.dev>

.gitattributes

@@ -0,0 +1,10 @@
+/examples           export-ignore
+/tests              export-ignore
+.gitattributes     export-ignore
+.github            export-ignore
+.gitignore         export-ignore
+CHANGELOG-*         export-ignore
+CODE_OF_CONDUCT.md  export-ignore
+CONTRIBUTING.md     export-ignore
+UPGRADING.md        export-ignore
+RELEASE.md          export-ignore

.gitignore

@@ -1,3 +1,7 @@
 vendor
 .DS_Store
+.idea/
 composer.lock
+.idea
+.fleet
+.vscode