Add crate for procedural macro for contract writing

[Daksh14]

We were discussing the possibility of generating the "boilerplate" code we see in contracts/alice/ through a procedural macro

@Neotamandua and @HDauven had discussion about behavior here dusk-network/dev-tools#1

@HDauven has an example which we can use as 0.1

https://github.com/HDauven/piecrust-macros

We should start by pushing a 0.1 first and then later figure out how to improve it

I replied to this disccusion here: dusk-network/dev-tools#2

[HDauven]

As discussed with @ZER0 before, we do not want to leak dev tooling into this repository. That's why we created the dev-tools repository, since everyone is free to build their own set of tools on top of our primitives.