s/one point per dot/one dot per point/

In the lecture video the professor said that dotchart consists of one dot per
point in the data and it seems reasonable as well. The slide was stating
this the other way round.
Remote repeated "of the" in the sentence.
Remove the.
Remove "it".
Merge pull request #5 from abhinav-upadhyay/lecture11-fix

Fixes in the slides of lecture 11