docs(relay-node): provide an example .env file

.env.example

@@ -0,0 +1,40 @@
+USER_PRIVATE_KEY=private_key
+ALCHEMY_API_KEY=api_key
+REDIS_HOST=localhost
+REDIS_PORT=6379
+PROVER_SERVER_HOST=http://127.0.0.1
+PROVER_SERVER_PORT=5000
+INITIAL_SLOT=5860953
+SLOTS_JUMP=32
+PRATTER=TRUE
+MAINNET=FALSE
+LC_GOERLI=0xf65B59bc947865490eF92D8461e8B5D0eA87c343
+LC_OPTIMISTIC_GOERLI=
+LC_BASE_GOERLI=
+LC_ARBITRUM_GOERLI=
+LC_SEPOLIA=
+LC_MUMBAI=
+LC_FUJI=
+LC_FANTOM=
+LC_ALFAJORES=
+LC_BSC=
+LC_AURORA=
+LC_GNOSIS=
+LC_CHIADO=
+LC_EVMOS=
+LC_MALAGA=
+GOERLI_HASHI=0x4169ea397fe83F55e732E11390807b3722374f78
+OPTIMISTIC_HASHI=''
+BASE_HASHI=''
+ARBITRUM_HASHI=''
+SEPOLIA_HASHI=''
+MUMBAI_HASHI=''
+FANTOM_HASHI=''
+ALFAJORES_HASHI=''
+CHIADO_HASHI=''
+EVMOS_HASHI=''
+MALAGA_HASHI=''
+AURORA_HASHI=''
+GNOSIS_HASHI=''
+FUJI_HASHI=''
+BSC_HASHI=''

README.md

@@ -188,6 +188,9 @@ LC_EVMOS=0x8E4D36CD13015EA6F384cab3342156b3dC5d0a53
 If you skip some of these variables, the relay node won't publish updates for
 the particular network.
 
+For a full list of supported ENV variables, please see the provided
+[example .env file](.env.example).
+
 ### How does the relayer work?
 
 We utilize BullMQ for our system.