chapter07.md: is there a reason why .shift() is not mentioned?

[Vse Mozhe Buty]

It seems to be a simple and useful method, easier than .splice() for the first element removing, and somehow lacking for complete symmetry with .push(), .unshift() and .pop().

[Baptiste Pesquet]

No real reason, this chapter evolved to meet the needs of other parts of the book. Presenting too many methods could become confusing for the reader, but shift() is a good candidate.

Thanks for the idea!