Improve documentation for the `else` branch of a `loop` statement

[Gerardwx]

Documentation

The current tutorial documentation on break and continue Statements, and else Clauses on Loops is confusing because some sentences are not always true by themselves, and it's not explicitly stated else's only make sense with break statements.

Linked PRs

• gh-123786: Clarify else clause in loop statements #123787

[StanFromIreland]

Closing as this has been completed per PR discussion.