[DOCS-386] Add extra context before coverage setup instructions

[prcr]

Type of feedback

• [ ] Bug or incorrect information
• [ ] Missing information
• [ ] Outdated information
• [X] Enhancement
• [ ] Other

Feedback

It could be beneficial to have a "Before you start" section on the coverage setup page providing a bit more context to users on how coverage works at Codacy, and which configurations the product expects to correctly present coverage data.

For example, we should make it clearer that we expect the CI/CD workflow of the users to upload coverage data:

• For all commits in all branches
  • Paying special attention to long-lived branches which may need to be updated with the coverage setup changes for Codacy to correctly report coverage for those branches
• Including coverage reports for the tests of all code in the repository and not just the changes in a commit or branch/pull request

Affected pages This feedback applies to the following documentation pages / URLs:

https://docs.codacy.com/coverage-reporter/

Additional context If applicable, provide any other context or information that could be useful in updating the documentation:

Validate with the Support team what are the most common questions that users ask regarding setting up coverage.

[github-actions[bot]]

Internal Jira issue: DOCS-386