Refactor task based docs

[ptodev]

This is an attempt to simplify and consolidate the examples and task based docs:

• The current docs are sometimes too verbose.
• The current docs are not consistent. Some use docker containers for examples, some use killercoda, some include a picture of the component graph. They all vary.
• The examples often include outdated practices and deprecated functionality.
• There is lots of duplication. E.g. there could be a task based doc with a certain Alloy config, and literally the same config may also be listed as an example in a component reference page
• Some examples in component reference pages list very elaborate examples which span several components. Those should be task based docs
• When users unfamiliar with Alloy browse the docs, they don't know what components to use. It'd be good to use the component reference only for component reference and list examples elsewhere.