Update README.md

Made very minor modifications to wording for correct English usage.  One typo in the reference to "...settings.py" corrected.
Update README.md

Very minor changes to wording after proofreading.  "Go to Post..." changed to "Go to Posts..." for consistency with the image that it refers to (although of course the model itself is named "Post", but it appears in the admin page as "Posts")
Minor wording changes after proofreading
Minor wording changes after proofreading
Merge pull request #29 from rebkwok/master

Proofreading changes