Fixed typos in final paragraph

In your explanation in the last full paragraph, you were saying "exports.welcome" when I believe you meant "exports.home."
Adding sudo to express install

npm install -g express would not run without the sudo command in front.
named the function 'home' but referred to it in the directions as 'welcome'
Deleted unnecessary 's' from the word 'commas'.  Simple grammar correction.
correcting the spelling of 'templating'.
More specific instructions for where to add the next line of code.
adding link to handlebars library to explain the directory structure.
Grammar correction.  Fixing a run-on sentence.
More specific instructions about where to put the next line of code.
spelling correction
Merge pull request #1 from soolaimon/patch-1

Fixed typos in final paragraph
Merge pull request #3 from ryanrombough/master

Adding sudo to express install
Merge pull request #4 from ryanrombough/patch-2

More specific instructions about where to put the next line of code.
resolved merging confilcts