Typo: Chapter 3 - Intro Section

[ablaberge]

In the plain text sample CLI, the sample user name is "oneils@mbp", but in paragraph 4 above the second plain text example, the user is referred to as "oneils@mpb" - notice the b and p are swapped. Easy fix :)

[ablaberge]

Same issue is present in the last paragraph of the "Getting Around the File System" section of Chapter 3.

[Leslie-C]

Corrected in #34, thanks!