Hardware libraries style guide

[nkrkv]

As mentioned in https://github.com/xodio/xod-docs/pull/63#issuecomment-420309723:

We have a few conventions that are scattered through the docs or even unwritten. For example:

We have a few conventions that are scattered through the docs or even unwritten. For example:

• any nodes that create a new type to work with hardware should be named as xxx-device
• node that initialises hardware module should be named init
• names of any nodes which do instructions "what to do" in imperative style must begin with a verb (init, read-byte, pair-tag, write-line, etc)
• nodes that "unfold" complex types into more primitive ones are named unpack-xxx
• example patches are named example-xxx (and probably a few others that I forgot to mention)

It will be cool to summarize these in a single guide article.

[brusherru]

Also, do not forget to replace xxx-example with example-xxx in the guide Creating Libraries