add env example

.gitignore

@@ -296,4 +296,4 @@ cython_debug/
 .idea/
 
 # Environment variables
-.env*
+.env.dev

backend/.env.example

@@ -0,0 +1,73 @@
+# Django
+DEBUG=
+SECRET_KEY=
+DATABASE_URL=
+
+# Heuy
+HUEY_REDIS_URL=
+HUEY_IMMEDIATE=
+HUEY_STORAGE_MAX_CONNECTIONS=
+
+# Circle.
+CIRCLE_ATTESTATION_BASE_URL=
+CIRCLE_SANDBOX_ATTESTATION_BASE_URL=
+
+# RPCs
+ETHEREUM_RPC_NODES=
+ETHEREUM_TESTNET_RPC_NODES=
+
+POLYGON_POS_RPC_NODES=
+POLYGON_POS_TESTNET_RPC_NODES=
+
+ARBITRUM_ONE_RPC_NODES=
+ARBITRUM_ONE_TESTNET_RPC_NODES=
+
+BASE_RPC_NODES=
+BASE_TESTNET_RPC_NODES=
+
+OPTIMISM_RPC_NODES=
+OPTIMISM_TESTNET_RPC_NODES=
+
+AVALANCHE_RPC_NODES=
+AVALANCHE_TESTNET_RPC_NODES=
+
+# CrossChainBridge
+CROSS_CHAIN_BRIDGE_ETHEREUM_DEPLOYED_ADDRESS=
+CROSS_CHAIN_BRIDGE_ETHEREUM_TESTNET_DEPLOYED_ADDRESS=
+
+CROSS_CHAIN_BRIDGE_AVALANCHE_DEPLOYED_ADDRESS=
+CROSS_CHAIN_BRIDGE_AVALANCHE_TESTNET_DEPLOYED_ADDRESS=
+
+CROSS_CHAIN_BRIDGE_BASE_DEPLOYED_ADDRESS=
+CROSS_CHAIN_BRIDGE_BASE_TESTNET_DEPLOYED_ADDRESS=
+
+CROSS_CHAIN_BRIDGE_OPTIMISM_DEPLOYED_ADDRESS=
+CROSS_CHAIN_BRIDGE_OPTIMISM_TESTNET_DEPLOYED_ADDRESS=
+
+CROSS_CHAIN_BRIDGE_POLYGON_POS_DEPLOYED_ADDRESS=
+CROSS_CHAIN_BRIDGE_POLYGON_POS_TESTNET_DEPLOYED_ADDRESS=
+
+CROSS_CHAIN_BRIDGE_ARBITRUM_ONE_DEPLOYED_ADDRESS=
+CROSS_CHAIN_BRIDGE_ARBITRUM_ONE_TESTNET_DEPLOYED_ADDRESS=
+
+# TokenMessenger
+TOKEN_MESSENGER_BASE_DEPLOYED_ADDRESS=
+TOKEN_MESSENGER_BASE_TESTNET_DEPLOYED_ADDRESS=
+
+TOKEN_MESSENGER_OPTIMISM_DEPLOYED_ADDRESS=
+TOKEN_MESSENGER_OPTIMISM_TESTNET_DEPLOYED_ADDRESS=
+
+TOKEN_MESSENGER_ETHEREUM_DEPLOYED_ADDRESS=
+TOKEN_MESSENGER_ETHEREUM_TESTNET_DEPLOYED_ADDRESS=
+
+TOKEN_MESSENGER_AVALANCHE_DEPLOYED_ADDRESS=
+TOKEN_MESSENGER_AVALANCHE_TESTNET_DEPLOYED_ADDRESS=
+
+TOKEN_MESSENGER_POLYGON_POS_DEPLOYED_ADDRESS=
+TOKEN_MESSENGER_POLYGON_POS_TESTNET_DEPLOYED_ADDRESS=
+
+TOKEN_MESSENGER_ARBITRUM_ONE_DEPLOYED_ADDRESS=
+TOKEN_MESSENGER_ARBITRUM_ONE_TESTNET_DEPLOYED_ADDRESS=
+
+# Deployer
+DEPLOYER_PRIVATE_KEY=