Issues in `.gitignore` that can cause build to fail due to missing packages during manual update site base on this template

[quangbhdang]

Describe the bug
When manually download the site source code and update it in user repository. There chance Line 15 in .gitignore will cause the _sass/vendor folder to be ignore when trying to push and commit to Git. This will cause the site to fail to build due to missing import packages.

To Reproduce
Steps to reproduce the behavior:

1. Have a previously setup github repository for Github Page
2. Download and unzip the source code from this template
3. Push and commit as normal
4. Github Actions build page will fail due to missing package import

Expected behavior
The Github Actions should be able to build and publish the site change as normal.

Browser

• OS: [Window WSL 2 Ubuntu] (My Development environment)
• Browser [Edge]
• Version [138.0.3351.77 Official Built]

Additional context
I previously use Minimal Mistake theme as my repository template thus I want to manually update to prevent deleting git history and modify my old content too much. However, after unzip the source code inside my repository this cause an issues during my regular push to build site.

[rjzupkoii]

Thanks for catching this!