fscontext 0.2.0

• Initial CRAN submission.
• Added support for observing ZIP archives using scan_storage().
• Added structural aggregation profiles (folder-depth-1 to folder-depth-4 and wacz) in derive_structural_groups().
• Added a vignette illustrating structural aggregation metadata, candidate Record Sets, and RiC-inspired contextual reconstruction using directories, ZIP archives, and WACZ packages.