Fixed spelling of Peyton Manning's first name. (#718)

docs/_docs/quick_start.md

@@ -252,7 +252,7 @@ In R, we use the normal model fitting API.  We provide a `prophet` function that
 # R
 library(prophet)
 ```
-First we read in the data and create the outcome variable. As in the Python API, this is a dataframe with columns `ds` and `y`, containing the date and numeric value respectively. The ds column should be YYYY-MM-DD for a date, or YYYY-MM-DD HH:MM:SS for a timestamp. As above, we use here the log number of views to Petyon Manning's Wikipedia page, available [here](https://github.com/facebook/prophet/blob/master/examples/example_wp_log_peyton_manning.csv).
+First we read in the data and create the outcome variable. As in the Python API, this is a dataframe with columns `ds` and `y`, containing the date and numeric value respectively. The ds column should be YYYY-MM-DD for a date, or YYYY-MM-DD HH:MM:SS for a timestamp. As above, we use here the log number of views to Peyton Manning's Wikipedia page, available [here](https://github.com/facebook/prophet/blob/master/examples/example_wp_log_peyton_manning.csv).
 
 ```R
 # R