Minor typos and spelling corrections in Introduction

With this commit, minor typos have been corrected in the Introduction
section. The majority of them are just small corrections, others are in
order to not use contractions ("did not" instead of "didn't" and so on).
Other modifications have been added with the aim of remove some small
portion of the phrases to make it more focused.

0 files changed, 0 insertions, 0 deletions