feat: update scripts to use env vars

- bitcoind entrypoint set chain value
- bitcoind healthcheck fix cli parameter
- lightning entrypoint script
- lightning health script
- prepend chain in bitcoin.conf

Signed-off-by: Lakshya Singh <lakshay.singh1108@gmail.com>

lightningd/healthcheck.sh

@@ -0,0 +1,15 @@
+#!/bin/sh
+
+set -ex
+
+LIGHTNING_NETWORK=""
+
+case $BITCOIN_CHAIN in
+    "test")    LIGHTNING_NETWORK=testnet ;;
+    "regtest") LIGHTNING_NETWORK=regtest ;;
+    "main")    LIGHTNING_NETWORK=bitcoin ;;
+    "signet")  LIGHTNING_NETWORK=signet ;;
+    *) echo "Invalid BITCOIN_CHAIN value: $BITCOIN_CHAIN" && exit 1 ;;
+esac
+
+lightning-cli --network $LIGHTNING_NETWORK getinfo