v0.3.0

Added

• add recursive directory upload with progress callback (#52)
• add auto-paginating stream iterators for list operations (#50)
• add methods to download actual file content (#48)
• add URL encoding for file paths with special characters (#47)

Other

• extract error types to dedicated module with contextual fields (#49)
• move a few things around (#36)
• replace manual cache steps with Swatinem/rust-cache (#35)
• reorganize handlers to match Files.com documentation categories (#33)