[ImgBot] optimizes images

*Total -- 6,973.85kb -> 6,322.31kb (9.34%)

/docs/reference/plot.Arima-1.png -- 35.66kb -> 20.85kb (41.52%)
/docs/reference/plot.Arima-3.png -- 39.77kb -> 23.94kb (39.82%)
/docs/reference/taylor-1.png -- 156.51kb -> 95.59kb (38.92%)
/docs/reference/mstl-1.png -- 177.39kb -> 135.76kb (23.47%)
/docs/reference/autoplot.ts-1.png -- 51.97kb -> 40.47kb (22.12%)
/docs/reference/seasonplot-2.png -- 174.87kb -> 138.55kb (20.77%)
/docs/reference/autoplot.seas-1.png -- 77.38kb -> 61.56kb (20.44%)
/docs/reference/gglagplot-1.png -- 281.84kb -> 228.68kb (18.86%)
/docs/reference/seasonplot-1.png -- 168.93kb -> 137.38kb (18.68%)
/docs/reference/gglagplot-2.png -- 342.10kb -> 284.12kb (16.95%)
/docs/reference/gglagplot-3.png -- 132.30kb -> 112.84kb (14.71%)
/docs/reference/seasonplot-3.png -- 158.94kb -> 135.62kb (14.67%)
/docs/reference/plot.Arima-5.png -- 37.96kb -> 32.50kb (14.38%)
/docs/logo.png -- 6.81kb -> 5.92kb (13.12%)
/man/figures/logo.png -- 6.81kb -> 5.92kb (13.12%)
/docs/reference/figures/logo.png -- 6.81kb -> 5.92kb (13.12%)
/docs/reference/tsdisplay-3.png -- 96.96kb -> 84.69kb (12.65%)
/docs/reference/plot.mforecast-1.png -- 68.53kb -> 60.13kb (12.25%)
/docs/reference/tsdisplay-1.png -- 97.67kb -> 85.72kb (12.23%)
/docs/reference/autoplot.ts-3.png -- 53.22kb -> 46.80kb (12.07%)
/docs/reference/gglagplot-4.png -- 230.82kb -> 203.07kb (12.02%)
/docs/reference/autoplot.seas-2.png -- 87.27kb -> 77.63kb (11.04%)
/docs/reference/plot.mforecast-2.png -- 93.25kb -> 83.03kb (10.96%)
/docs/reference/accuracy-1.png -- 46.36kb -> 41.48kb (10.53%)
/docs/reference/seasonal-2.png -- 67.37kb -> 60.77kb (9.8%)
/docs/reference/plot.mforecast-4.png -- 70.17kb -> 63.57kb (9.4%)
/docs/reference/plot.ets-3.png -- 60.73kb -> 55.10kb (9.28%)
/docs/reference/forecast.HoltWinters-1.png -- 35.01kb -> 31.78kb (9.23%)
/docs/reference/plot.mforecast-3.png -- 48.33kb -> 44.08kb (8.81%)
/docs/reference/gglagplot-5.png -- 127.34kb -> 117.32kb (7.87%)
/docs/reference/plot.ets-2.png -- 65.50kb -> 60.68kb (7.37%)
/docs/reference/fourier-2.png -- 160.27kb -> 148.91kb (7.08%)
/docs/reference/plot.Arima-4.png -- 71.24kb -> 66.26kb (6.99%)
/docs/reference/naive-1.png -- 28.22kb -> 26.26kb (6.96%)
/docs/reference/forecast-1.png -- 34.02kb -> 31.66kb (6.94%)
/docs/reference/naive-2.png -- 33.89kb -> 31.63kb (6.68%)
/docs/reference/splinef-1.png -- 35.46kb -> 33.10kb (6.66%)
/docs/reference/residuals.forecast-1.png -- 53.47kb -> 49.91kb (6.66%)
/docs/reference/auto.arima-1.png -- 33.75kb -> 31.64kb (6.28%)
/docs/reference/forecast.Arima-1.png -- 33.98kb -> 31.91kb (6.08%)
/docs/reference/mstl-2.png -- 72.43kb -> 68.05kb (6.05%)
/docs/reference/plot.Arima-6.png -- 61.11kb -> 57.55kb (5.83%)
/docs/reference/nnetar-2.png -- 69.33kb -> 65.69kb (5.25%)
/docs/reference/croston-1.png -- 28.95kb -> 27.48kb (5.08%)
/docs/reference/plot.forecast-4.png -- 37.33kb -> 35.48kb (4.97%)
/docs/reference/nnetar-3.png -- 70.44kb -> 66.96kb (4.93%)
/docs/reference/forecast.baggedModel-1.png -- 33.57kb -> 31.93kb (4.88%)
/docs/reference/tslm-1.png -- 45.91kb -> 43.68kb (4.85%)
/docs/reference/forecast.lm-1.png -- 45.22kb -> 43.04kb (4.82%)
/vignettes/jsslogo.jpg -- 22.20kb -> 21.14kb (4.79%)
/docs/reference/seasonaldummy-2.png -- 39.35kb -> 37.48kb (4.75%)
/docs/reference/gold-1.png -- 37.41kb -> 35.65kb (4.71%)
/docs/reference/plot.Arima-2.png -- 54.93kb -> 52.40kb (4.61%)
/docs/reference/ses-1.png -- 32.17kb -> 30.69kb (4.6%)
/docs/reference/arfima-1.png -- 50.86kb -> 48.54kb (4.58%)
/docs/reference/Acf-2.png -- 21.03kb -> 20.09kb (4.44%)
/docs/reference/Acf-1.png -- 20.86kb -> 19.94kb (4.42%)
/docs/reference/woolyrnq-1.png -- 47.65kb -> 45.56kb (4.39%)
/docs/reference/gas-3.png -- 51.35kb -> 49.12kb (4.34%)
/docs/reference/baggedModel-1.png -- 33.90kb -> 32.43kb (4.33%)
/docs/reference/wineind-1.png -- 64.21kb -> 61.46kb (4.28%)
/docs/reference/forecast.StructTS-1.png -- 32.85kb -> 31.48kb (4.19%)
/docs/reference/seasonal-1.png -- 65.77kb -> 63.05kb (4.13%)
/docs/reference/tsdisplay-2.png -- 42.34kb -> 40.61kb (4.08%)
/docs/reference/ggmonthplot-1.png -- 73.53kb -> 70.61kb (3.97%)
/docs/reference/autoplot.acf-3.png -- 28.86kb -> 27.93kb (3.21%)
/docs/reference/Arima-1.png -- 54.08kb -> 52.40kb (3.1%)
/docs/reference/CVar-2.png -- 27.40kb -> 26.55kb (3.09%)
/docs/reference/Arima-2.png -- 58.07kb -> 56.33kb (3%)
/docs/reference/autoplot.acf-1.png -- 23.86kb -> 23.17kb (2.91%)
/docs/reference/seasadj-1.png -- 58.73kb -> 57.05kb (2.85%)
/docs/reference/autoplot.acf-2.png -- 22.47kb -> 21.86kb (2.75%)
/docs/reference/BoxCox.lambda-1.png -- 49.70kb -> 48.34kb (2.74%)
/docs/reference/forecast.stl-3.png -- 49.95kb -> 48.59kb (2.71%)
/docs/reference/plot.forecast-5.png -- 46.37kb -> 45.13kb (2.68%)
/docs/reference/checkresiduals-1.png -- 103.15kb -> 100.42kb (2.65%)
/docs/reference/ggmonthplot-2.png -- 78.72kb -> 76.81kb (2.42%)
/docs/reference/nnetar-1.png -- 62.08kb -> 60.66kb (2.29%)
/docs/reference/forecast.nnetar-1.png -- 62.11kb -> 60.70kb (2.27%)
/docs/reference/sindexf-1.png -- 68.48kb -> 67.15kb (1.95%)
/docs/reference/plot.forecast-3.png -- 107.64kb -> 105.66kb (1.83%)
/docs/reference/meanf-1.png -- 58.99kb -> 57.93kb (1.8%)
/docs/reference/thetaf-1.png -- 60.15kb -> 59.07kb (1.79%)
/docs/reference/fourier-1.png -- 86.84kb -> 85.29kb (1.79%)
/docs/reference/seasonaldummy-3.png -- 63.56kb -> 62.44kb (1.75%)
/docs/reference/seasonaldummy-4.png -- 63.56kb -> 62.44kb (1.75%)
/docs/reference/forecast.Arima-2.png -- 49.80kb -> 48.98kb (1.64%)
/docs/reference/simulate.ets-1.png -- 65.95kb -> 64.89kb (1.62%)
/docs/reference/ets-1.png -- 62.91kb -> 61.89kb (1.61%)
/docs/reference/CVar-1.png -- 145.76kb -> 143.46kb (1.58%)
/docs/reference/fitted.Arima-1.png -- 85.88kb -> 84.58kb (1.51%)
/docs/reference/gghistogram-1.png -- 45.59kb -> 45.01kb (1.26%)
/docs/reference/forecast.ets-1.png -- 66.06kb -> 65.24kb (1.24%)
/docs/reference/ses-2.png -- 68.23kb -> 67.41kb (1.2%)
/docs/reference/forecast.stl-1.png -- 72.82kb -> 71.96kb (1.19%)
/docs/reference/plot.forecast-2.png -- 102.90kb -> 101.72kb (1.14%)
/docs/reference/forecast.stl-2.png -- 64.56kb -> 63.85kb (1.1%)
/docs/reference/ma-1.png -- 87.02kb -> 86.67kb (0.41%)
/docs/reference/naive-3.png -- 78.05kb -> 77.90kb (0.19%)