Add learning objectives for functional programming

[eirini-zormpa]

There are currently no objectives for the lessons on Gutenberg, even though the original material actually did have them. I'll add the missing objectives here until we figure out how to incorporate them to the materials.

link to original materials

---

Objectives:

• Describe the core concepts that define the functional programming paradigm
• Describe the main characteristics of code that is written in functional programming style
• Learn how to generate and process data collections efficiently using MapReduce and Python’s comprehensions

---

Notes:

• the original material has been expanded and split into "sub-lessons", it's likely that there is material that goes beyond the original learning objectives
• because of the different structure on Gutenberg, not all objectives appear in the same episode anymore and should be divided to reflect the material that actually exists on the page.