Add artisan command to initialise sketchpad reload

[davestewart]

Would be cool to be able to type

php artisan sketchpad:init

Which would:

• download and install sketchpad reload
• create the sketchpad.json file
• write the correct javascript and paths into the file

Optionally, you could

• update git ignore
• run sketchpad reload
• change the install folder (root, or sketchpad folder)

The command would use the existing options in storage to make choices, and could also ask the user questions.

Should also ask where you want node_modules to be installed:

• /
• /sketchpad
• /other

Additionally, could include in setup.