chore: config assets for multiple chains

- lightning config
- env vars
- bitcoin.conf for different networks
- copy configs in lightningd repo
Signed-off-by: Lakshya Singh <lakshay.singh1108@gmail.com>

lightningd/Dockerfile

@@ -97,6 +97,8 @@ RUN mkdir -p "${BITCOIND_HOME}" && \
 
 COPY assets/bitcoin.conf "${BITCOIND_HOME}"/bitcoin.conf
 COPY assets/testnet-config /testnet-config
+COPY assets/regtest-config /regtest-config
+COPY assets/main-config /main-config
 
 USER lightning