v0.5.1

This release includes some stabilizations, conveniences and UX improvements:

• Change config to flag (#300)
• Add ZELLIJ environment variable on startup (#305)
• Terminal fix: do not clear line if it's not there (#289)
• Do not allow opening new pane on the status bar (#314)
• Allow scrolling by full pages (#298)
• Reduce crate size by 4.8MB using cargo diet, to 77kB (#293)
• Draw UI properly when instantiated as the default terminal command (#323)
• Resolve ambiguous pane movements by their activity history (#294)