[FIX] ; [IMP] $grid & demo ; [ADD] modula.js and package.json

[FIX]
mat3, mat4: wrong import path
rect, transform2: forgotten bracket

[IMP]
demo data
split grid to grid and $grid

[ADD]
$grid.js
modula.js: to auto load all files
package.json: for node.js (with main = modula.js)