Update documentation for sits version 1.5.1

[Gilberto Camara]

Include in the sitsbook all new functions implemented in sits 1.5.0:

• Support for SENTINEL-1-RTC and SENTINEL-2-L2A in CDSE
• Include support for DEA products SENTINEL-1-RTC, LS5-SR, LS7-SR, LS9-SR, ALOS-PALSAR-MOSAIC, NDVI ANOMALY, DAILY CHIRPS, MONTHLY CHIRPS and DEM-30
• Support for Sentinel-1 GRD and RTC collections from Planetary Computer
• Include parameter tile to select data from Sentinel-1 (MPC)
• Include parameter tile to select data from Sentinel-1 and Sentinel-2 (DEAFRICA)
• Include parameter tile to select data from HLS collections
• Improved support for GPU-based classification of deep learning models
• Support for non-normalized derived indexes
• Support for shapefiles as ROI in sits_cube()
• Fix inconsistencies in HLS scale factors
• New function to obtain ROI based on MGRS tiles
• Add support for uncertainty cubes in sits_mosaic()
• Improve performance of sits_segment() using chunk parallelization
• Include uncertainty measures for vector probability cubes
• New sits_clean() function to improve classified maps
• New functions sits_sampling_design() and sits_stratified_sampling()
• New sits_reduce() function
• Include dtw distance when building SOM maps