Add Code Coverage instructions

[ZakkeryDaRebel]

Overview

With the introduction of Line Code Coverage, we will need to update the specs to reflect this change

This issue is connected with softwareconstruction240/autograder#398

To Do

Phase 3

• First off, we will want to add instructions on how to run code coverage using JaCoCo on IntelliJ 2024 edition or sooner. This will probably go nicely in Phase 3 Getting Started or in its own instructions page

Phase 5

• We will need to update the Phase 5 specs on the UnitTest. For example, we will need to tell the students to put their tests in the same file as the stated in this issue. Code Coverage Phase 5 Addition chess#47

Rubric

• We will need to update the Rubric for the Unit Tests to no longer say that there needs to be one positive and one negative test for each method, but instead state that there should be enough Unit Tests to achieve the required amount of code coverage (80% unless professors have changed their mind).
• In addition, if all the Professors like the idea of adding extra credit if students reach a certain threshold above the required line coverage amount, then we will need to update the Rubrics of Phases 3-5, adding the extra credit as a separate row, which will also affect the autograder's rubric items as well.