Described missing Datasets and fixed wrong number in exercise_deep_learning

notebooks/data/Auto_mpg/README.md

+# Context
+
+Mileage per gallon performances of various cars. The data is technical specs of cars.   
+Origin: This dataset was taken from the StatLib library which is
+maintained at Carnegie Mellon University. The dataset was
+used in the 1983 American Statistical Association Exposition.
+(c) Date: July 7, 1993
+
+# Content
+
+The dataset has 398 entries and 9 attributes.
+This file contains the basic information (mpg, cylinders, displacement, horsepower, weight, acceleration, model year, origin, car name) about the cars. Be careful, there are 6 invalid values in the 'horsepower' column.
+
+# Example Entries
+
+|mpg|cylinders|displacement|horsepower|weight|acceleration|model year|origin|car name|
+|----|----|----|----|----|----|----|----|----|
+|18|8|307|130|3504|12|70|1|chevrolet chevelle malibu|
+|15|8|350|165|3693|11.5|70|1|buick skylark 320|
+|18|8|318|150|3436|11|70|1|plymouth satellite|
+|16|8|304|150|3433|12|70|1|amc rebel sst|
+|17|8|302|140|3449|10.5|70|1|ford torino|
+
+
+# Credit
+
+Dataset acquired from [Kaggle](https://www.kaggle.com/uciml/autompg-dataset)
+