Replace bash scripting with Javascript

[pascalw]

This PR replaces all bash scripting with pure Javascript. Main advantage is that this improves compatibility with Windows and in general it's nicer if everything is written in Javascript.

A couple of other notable changes that I made in the process:

• Moved new project creation to a separate package, create-maji-app.
  • This has the advantage of being able to use the yarn create workflow, e.g. yarn create maji-app com.example.myapp ~/Code/myapp.
  • It also keeps the dependencies of the main package lighter.
• Use an embedded Yeoman generator to create the project.
  • This makes it easier in the future to ask questions during project creation, for example 'Typescript or Javascript?`.
  • Yeoman generators can be ran on existing projects. This makes it easier to update existing projects with new template changes.
• Use Husky and lint-staged for Git hooks.
  • Our previous Git hooks were using a lot Unix tools and thus are not ideal for Windows. Husky requires /bin/sh but from what I read Git installations on Windows usually include this. See https://github.com/typicode/husky/issues/228 for details.

[pascalw]

I made a boo-boo publishing 3.2.0 under the beta tag. I'm not sure if we can later still publish 3.2.0 from master under a non beta tag, so we might have to go to 3.2.1 immediately.

I unpublished 3.2.0 now, however now I can't publish a new version of the maji-create-app package in the next 24 hours, probably because it's a new package? I'll republish this tomorrow as 3.2.0-beta.1.

[pascalw]

Ok packages are now published as 3.2.0-beta.1. So you can now try this with: yarn create maji-app com.example.myapp myapp.

[pascalw]

Ok I fixed two small issues I noticed and restored bin/setup, but in Node instead of Bash.

I also give this thing a try on Windows and creating a new project works, with the caveat that it requires Administrator permissions because we create a symlink from cordova/www -> ../dist/. There are still a few issues building and running the project due to how we treat environment variables, but given that the primary goal of this PR was to get rid of the Bash scripting and not Windows support I would still like to merge this now and fix remaining Windows issues in a separate PR.

@leonderijke @matthijsgroen @ruisalgado agree and :shipit: ?

[leonderijke]

Yes, :shipit:!