Add Goerli contracts addresses to documentation

We already had Ropsten and Mainnet addresses in this doc so I figured we
could add Goerli.

Author: nkuba

docs/rfc-2-vending-machine.adoc

@@ -109,3 +109,21 @@ The vending machine contracts are not upgradeable.
 * NU Staking Escrow address: `0x25C5aF106C04e17d7097617C5d74e23717Fb6286`
 * Keep Stake address: `0xE53eC3b651EEFA922dCc80c70426764aF4F7eFC0`
 * Token Staking address: `0x7149bC2d6f090fBcdc44303F0752ae34d77f6D71`
+
+=== Görli Testnet
+
+The most recent package deployed to Görli is published to the npm Registry
+and tagged with _goerli_ (`@threshold-network/solidity-contracts@goerli`).
+
+Currently it is: `@threshold-network/[email protected]`.
+
+Contracts addresses:
+
+* NU<>T Vending Machine address: `0x413ff6Bb6E12df17d99C1b12CbeD276c51EAc900`
+* KEEP<>T Vending Machine address: `0xBb9b1E617d739ec3034537A48f8cB62f80a181C5`
+* T token address: `0x0f092E3bd92751FDAe3765BCE3F6AeBe5881C499`
+* NU token address: `0x805336B10809e945302F6DdcDD07E61ecDfB2E08`
+* KEEP token address: `0x22647FfAe391540d584599818CA22fdF18890753`
+* NU Staking Escrow address: `0xAD83f62aD063B5af9F9E3F2F6772108473C0F03B`
+* Keep Stake address: `0xe65E4C75df3c446F477A0f1F2909Fc2c49d5e238`
+* Token Staking address: `0x0754935436b7DC24b62Bc8a01054A108A784d0f8`