Keyboard shortcut design

Overview

This document contains design ideas on how to add a consistent keyboard shortcut scheme for Petmate.

List of bugs tagged with the "keyboard" label: https://github.com/nurpax/petmate/labels/keyboard

Current keyboard shortcuts

• ESC - reset brush selection (e.g., clear current brush, switch to brush select mode)
• a,s,d,w - move the selection cursor in the char selector
• left/right arrows - move to prev/next screen
• open/save/undo/redo - these use platform native shortcuts

What more do we want?

• single key shortcuts to switch between painting tools (draw, colorize, brush, etc.)
• various "mode switch" key combinations like maybe holding shift to get vertical/horizontal movement lock for drawing straight lines (#9)