Added dynamic ingredients scaling.

[KN4CK3R]

A different implementation of dynamic scaling of ingredients like in #22

+ No ingredient "parsing"
- Needs recipe changes

Preview:

[KN4CK3R]

I have experimented with different ingredient formats but I'm not sure which is more useful.

ingredients:
- 4|bananas
- 0.5|cup|butter
- 100|g|sugar
- salt

Pro: easy to use and understand (as a programmer)
Contra: custom format to parse

ingredients:
- bananas:
  - 4
- butter:
  - 0.5
  - cup
- sugar:
  - 100
  - g
- salt

Pro: seperated parts
Contra: verbose format (and maybe difficult (don't forget the colon))

What do you think?