ML00 ex08: Interlude + Examples' cost

[mli42]

• Day: 05
• Exercise: 08

There is an interlude for ex08 that explains how to vectorize the loss calculation, thus it should be for ex07 and not ex08.

Also I noticed the change of the word cost for the word loss, but in the examples plots, it is still cost.

Moreover, the value of the cost seems to be the MSE and not the loss we were asked to reimplement on the previous exercice (on all the three examples).

Fixed on:

• [ ] Interlude
  • [ ] Github
  • [ ] Gitlab
• [ ] Examples' cost
  • [ ] Github
  • [ ] Gitlab