new tsa chapter

book/time_series/acf.md

book/time_series/ar.ipynb

book/time_series/ar.md

book/time_series/ar_exercise.ipynb

book/time_series/components.md

book/time_series/exercise1.ipynb

book/time_series/exercise3.ipynb

book/time_series/figs/signal_noise.png

book/time_series/figs/tsa_cover.png

book/time_series/fit_BLUE.ipynb

book/time_series/forecasting.md

book/time_series/generated_time_series.csv

book/time_series/intro.md

book/time_series/intro_graph.ipynb

book/time_series/modelling.md

book/time_series/noise.ipynb

book/time_series/stationarity.md

book/time_series/y_values.csv