Add doc deprecation for karma-jasmine with recommendations

[trivikr]

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

karma has been deprecated karma-runner/karma#3846

For browser-based unit testing solutions, karma recommends Web Test Runner and jasmine-browser-runner. For Node.js, it recommends Jest and Vitest.

There's no such deprecation notice in karma-jasmine which is an extension for karma

Describe the solution you'd like

Add doc deprecation in README, recommending readers to:

• try jasmine-browser-runner for real browser tests.
• no change if switching to Jest, as it has native support for jasmine.
• no change if switching to vitest, as it has native support for jasmine.

Describe alternatives you've considered

N/A