Add “Getting Started” guide

[geigerzaehler]

#Closes #1

The guide serves as an entry point for FFnet participants.

We assume the readers are familiar with the basic concepts and terminology of blockchain technology.

After reading the guide the reader should:

• be able to continuously run a node that participates in the network.
• be able to configure the node so that it mines blocks and the reader receives rewards in a wallet they control.
• be able to validate whether the node successfully participates in the network. i.e:
  • is connected
  • receives new blocks
  • mines blocks
• be able to obtain some RAD for their own account and transfer it
• be able / know how to run some queries against the ledger
• be able / know how to submit some transactions against the ledger

Topics that we want to cover are

• How to install the node and build it from source (See Add instructions to build the project from source radicle-registry#318)
• Where to get support from
• nodes - full and mining
• interacting with the ledger

Related issues

• Provide FFnet binaries
• Add instructions to build the project from source
• Log when mining is successful or we start mining on another block

[NunoAlexandre]

• Reach out section