Switch from bash scripts to higher language

[viceice]

We need to decide to which higher language we switch, because we've some features which are prettey complex to implement inside bash scripts.

So Idea's / preferences?

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• Automatic runtime install of tools #101

[viceice]

We decided to use the node ecosystem and write our main code inside typescript. That way we can easily support customer tools via custom javascript files imported at runtime. Another benefit is that we can reuse renovate datasource code.

Compiling can be done with pkg so we get a single small binary.

We can probably maintain compabillity to old tools by leaving some helper shell scripts, which are called from node.