Add crispEdges option for SVG output in JavaScript - #134

This PR adds a crispEdges option to createSvgTag() in the JavaScript implementation.

The new option supports three modes:

• 'auto' (default): adds shape-rendering="crispEdges" only for whole-number cellSize values
• true: always adds shape-rendering="crispEdges"
• false: never adds shape-rendering="crispEdges"

This fixes the rendering issue described in the PHP PR #104, while implementing the solution for the JavaScript version.

The default auto behavior keeps sharp rendering where it makes sense and avoids unwanted artifacts for fractional sizes:

• for whole-number cell sizes, cell boundaries align with the pixel grid, so crispEdges does not introduce geometric distortion
• for fractional cell sizes, forcing crispEdges can shift cell boundaries to the pixel grid and distort the geometry
• in practice, fractional cell sizes are usually not a meaningful target for QR modules anyway

Changes:

• add crispEdges option to createSvgTag(opts)
• update JavaScript distribution files
• update TypeScript declarations
• update README
• add test coverage for auto, forced enable, and forced disable