Add .gitattributes file to manage line endings

[WajahatKanju]

Pull Request: Config Compatibility - Line Endings Fix

Description:
This pull request addresses a configuration compatibility issue related to line endings when setting up the Django project using Docker on Windows. The problem arises from the docker-entrypoint.sh file having Windows line endings (CRLF) instead of the expected Linux line endings (LF), causing script execution errors during docker-compose up.fix issue #1467 and #990

Changes Made:

1. Added a .gitattributes file to the repository to specify LF line endings for .sh files.

Steps to Reproduce:

• Clone the Django project on a Windows machine.
• Follow instructions in the documentation under "Running Locally with Docker."
• Run docker-compose build and docker-compose up.
• Observe the error related to docker-entrypoint.sh script execution.

Expected Results:

• The docker-entrypoint.sh file should maintain its original Linux line endings (LF) and execute correctly in the Docker environment.

Actual Results:

• The file's line endings are converted to Windows style (CRLF), leading to execution problems in Docker. This issue occurs only on Windows when lines are auto-converted to CRLF.

Environment:

• Operating System: Windows 10
• Docker Version: 24.0.7, build afdd53b

Proposed Solution:

• Added a .gitattributes file to manage line endings for .sh files.
• Updated documentation to guide Windows users in configuring Git for correct line endings.

Contributor's Note:
I have tested the changes on my local environment, and they resolve the line ending issue. This pull request is submitted in accordance with the Django project's contribution guidelines.

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Checklist:

• All existing tests pass.