Update checkout action and add .gitignore

Upgraded GitHub Actions checkout from v3 to v5 in the workflow file for improved features and security. Added a .gitignore file to exclude IDE settings and environment files from version control.

Author: Pleasurecruise

.github/workflows/cnb.yml

@@ -5,7 +5,7 @@ jobs:
   sync:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v5
         with:
           fetch-depth: 0
 

.gitignore

@@ -0,0 +1,3 @@
+.idea/
+.vscode/
+.env