feat(07): add third solution to exercise 07 using 'or' function

[NachoVazquez]

PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[x] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Documentation content changes
[ ] Other... Please describe:

What is the current behavior?

Exercise 07 solutions don't contain the "or" usage alternative

Fixes: #4

What is the new behavior?

Exercise 07 has a third solution using the "or" function from Zod