[Coverage onboarding UI] Show how to generate a coverage report in your CI

[Adal3n3]

Problem

We have a small percentage of new users who are not familiar with coverage reports. It's important to provide guidance and help them generate a coverage report so they can use the Coverage feature.

On the Test Analytics side: we do show examples on how to generate JUnit XML files before the upload instruction.

Describe the solution you'd like

1. Provide a list of languages we support or at least starts from the most common one -DONE
2. Be specific on the 3 types of coverage report formats: .xml .json .txt that Codecov supports
3. The copy and paste code snippets to output a coverage report based on the customer used language and file type.
4. On the onboarding UI for Coverage Step 1: show how to output/generate a coverage report. Dropdown to select a language and a file type.

Figma: link Notion: link

[Adal3n3]

• We are going to shorten the dropdown selection to these 4: JS vitest, JS jest, Python, Go.
• We are providing examples for the final GitHub Actions workflow based on the selected language.
• Provide link doc to https://docs.codecov.com/docs/supported-languages

[Adal3n3]

@katia-sentry can you assign this issue? Thanks!