Create readme when auto Generating an example plugin

[macdja38]

It would be nice when using the plugin generator if a readme with the instructions on how to install the plugin that was created.

Create react app does a decent job of this when you use it to bootstrap a react project. https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md

Most importantly this should include the install steps for the the npm package as well as npx cap sync etc.

It'd be cool if this went a step further and automatically populated the package name in the install command, seeing as the user is asked to give that on plugin creation.

[lisagale]

I got lost

[imhoffd]

Related: #15

[distante]

Maybe this also related: ionic-team/capacitor#3605 (comment)

although, it could just be my inexperience with android configuration.