uji v0.0.2

Rebuild of the CLI on top of v0.0.1: June-to-Uji rename across providers and docs, new uji update self-updater, plus provider and docs additions.

Asset: uji-v0.0.2-darwin-arm64.tar.gz (macOS, Apple silicon), sha256 beside it.

Fresh install:

curl -fsSL https://raw.githubusercontent.com/Itsnotaka/uji/main/install.sh | sh

Existing installs: run uji update.