Contextual help system

See the full list of keybindings and information + tips on the current focused widget.

Jump mode label

ESC to dismiss added to bottom of Jump overlay.

Changelog

• Adds the contextual help system. Press f1 or ctrl+? (i.e. ctrl+shift+/) to see all bindings and extra information/hints about the widget you're currently focusing.
• No longer shift focus from data tables when using arrow keys (except in key-value editors).
• Cursors in inputs and text areas will no longer continue to blink in the background when a modal is open.
• Adds a small note at the bottom of the Jump Mode overlay indicating how to dismiss the overlay.

• Dynamic help by @darrenburns in #39

Full Changelog: 1.2.0...1.3.0