NoMongo: Update the CONTRIBUTING.md Testing section to cover jest and vitest

[palisadoes]

Is your feature request related to a problem? Please describe.

1. Last year we began the conversion from Jest to vitest testing
2. The GitHub Action shows the commands to run both sets
   1. https://github.com/PalisadoesFoundation/talawa-admin/blob/develop-postgres/.github/workflows/pull-request.yml
3. The testing documentation doesn't show this differentiation

Describe the solution you'd like

1. Update CONTRIBUTING.md
   1. https://github.com/PalisadoesFoundation/talawa-admin/blob/develop-postgres/CONTRIBUTING.md
2. Create separate sections for Jest and Vitest testing on:
   1. Running a single test
   2. Running all tests
   3. Viewing the code coverage of a single test file
   4. Viewing the code coverage of all test files
3. Create a section for testing all Jest and Vitest tests combined to:
   1. Determine the code coverage for the entire repository

Describe alternatives you've considered

• N/A

Approach to be followed (optional)

• N/A

Additional context

Related Issues:

• NoMongo: Update the CONTRIBUTING.md Testing section to cover jest and vitest #3270
• NoMongo: Restore Test CodeCov GitHub Action to the develop-postgres branch talawa-api#2854

Potential internship candidates

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

• Student Internship Programs talawa#359

[aadhil2k4]

@palisadoes I want to work on this issue