ell only prints usage

[bug] Wrong log levels

[feat] Test automation

[feat] POSIX compliant

[feat] Additional Compatibility and Dependency Requirements

[bug] Cannot force ell into terminal mode or write-to-file mode with TO_TTY

[bug] Fails at `read -r -N 1` on Mac OS

[bug] The output in the demo video is misleading

[feat] support acquiring credentials from system keyring

[feat] Read configuration from XDG_CONFIG_HOME