example(instance-mode): improve examples

example: update core bundle in examples

docs(README): update file size for min bundle

example: update core version in examples

example: update core version

docs(README): update dist files approx. file sizes

feat: multiple improvements

* added markers to mark code that does not belong to the core version
* npm scripts
  * renamed "build:macos" to "build-min:macos"
  * added "build-core:macos" to create p5.grain core version
  * added "build:macos" to execute "build-min:macos", "build-core:macos" and "dist-core:macos"
* added support to animate SVGElement (limited compatibility for Safari)
* dist directory is now commited to repository
* examples
  * use p5.grain core version
  * removed p5.grain minified version, but keep reference in index.html
* updated README
* bumped version to 0.3.0

patch(npm): update scripts and files