message: docs: Add testnet approval and staking instructions
diff: @@ -69,6 +69,29 @@ indexer. The only requirement is a minimum stake of 100k GRT.
  In order to register for the testnet and have testnet GRT distributed to you,
  please fill out the [testnet registration form](https://airtable.com/shrL1trS84Jf0aawP).
  +### Approving And Staking
  +
  +To approve your testnet GRT to be spent through the staking contract, first approve
  +it in the GRT contract:
  +
  +```bash
  +git clone https://github.com/graphprotocol/contracts
  +cd contracts
  +
  +./cli/cli.ts -m <indexer-mnemonic> -p <ethereum-rinkeby-node> \
  + contracts graphToken approve --account 0x2d44C0e097F6cD0f514edAC633d82E01280B4A5c --amount <grt>
  +```
  +
  +Afterwards, stake this amount:
  +
  +```bash
  +git clone https://github.com/graphprotocol/contracts
  +cd contracts
  +
  +./cli/cli.ts -m <indexer-mnemonic> -p <ethereum-rinkeby-node> \
  + contracts staking stake --amount <grt>
  +```
  +
  ### Setting An Operator
  To set an operator for your testnet indexer, you can use the contracts CLI as follows.
  