Improved resize handle placement options

• Removed old overlayHandle property and replaced with resizeHandlePlacement property allowing more resize handle placement options
• Moved resize handle styling to dynamically added style blocks instead of adding inline styles
• Added resizeHandlePlacement property docs to storybook
• Reimplement outer and inner space element from current live version for consistency

Fixed broken `overlayHandle` functionality

• Fixed overlayHandle property on resizable spaces which was broken in 0.1.25

Added proptypes as dependency to library

• Ensure proptypes package added as direct dependency to library so that proptypes is added automatically to downstream projects to ensure correct running of the library

Fixed broken 'handleSize' functionality

• Fixed issue where handleSize property was not being passed to internal ResizeHandle component

Reworked resize handle implementation with bigger touch handles

• Updated storybook to version 6.0.5
• Moved location of resize handle elements from within the space they resize up into the parent to allow better placement options outside of the bounds of the resizable space
• Revised resize handle implementation to match current live version
• Added touch handle functionality allowing larger touch areas for resize handles
• Fixed missing touch-action: auto; on scrollable spaces

Fixed broken resize event functionality

• Fix for broken onResizeStart and onResizeEnd events

First revision of major rework of state implementation

• Implemented global state implementation (issue #69)
• Added JEST testing for core space behaviour (issue #71)
• Major refactor of component structure / file structure
• Rewrote core state management for all spaces using global state
• Moved space dynamic styling updates from React managed with a React portal to direct DOM manipulation
• Added DOMRect as second parameter to onResizeEnd callback
• Fixed "Cannot update a component from inside the function body of a different component" from latest version of React - 16.3.0 (issue #64)
• Fixed issue where changing space anchors in the same parent 'ate' space incorrectly from a <Fill /> space (issue #52)

Replaced old demo projects with storybook docs and refactored resize logic

• Added storybook docs. View with npm run storybook.
• Remove old demo/next js projects
• Refactored file locations
• Refactored resize/drag logic
• Added prettier to project

Fixed readme in NPM package and added changelog

• Fixed NPM readme
• Added CHANGELOG.md

Styling fixes for height and z-index applied to spaces

• Fixed generation of head styles height and z-index which were missing a semi-colon.