Update Pull Request Template to Enforce Standards

[varshith257]

Problem We need to ensure contributors follow repository standards, including implementing coderaabbitai suggestions and maintaining test coverage. This is currently not enforced via the PR template.

Proposed Solution Update the Pull Request (PR) template to include:

-[ ] A checklist for implementing coderaabbitai suggestions.

-[ ]A checklist for verifying that tests are written for changes made in PR and coverage meets or exceeds current test coverage (~90/95).

Acceptance Criteria

• A PR template is updated in the .github directory.
• The template includes a checklist for coderaabbitai suggestions and test coverage.

Potential internship candidates

Please read this if you are planning to apply for a Palisadoes Foundation internship

• https://github.com/PalisadoesFoundation/talawa/issues/359

NOTE Submit PRS for both branches develop and develop-postgres

[adithyanotfound]

please assign