Exercise 1 typos

[rsperberg]

In Babel Setup, the text reads:

Once you saved, it you will be able to run the program like this:

The word "have" has been omitted and "it" should appear before the comma, not after. The text should read:

Once you have saved it, you will be able to run the program like this:

or

Once you have saved the file, you will be able to run the program like this:

In the first line after the Exercise heading, the word "the" is repeated:

Create a javascript program that takes the the first command-line argument and
outputs it right after a "Hello " String using ES6 template strings.

The redundant "the" should be removed so that the text reads like this:

Create a javascript program that takes the first command-line argument and
outputs it right after a "Hello " String using ES6 template strings.