chore: Update documentation for custom smart contracts #4327

Job	Run time
docker	2m 23s
build	2m 45s
e2e-test (ethereum, evmconnect, TestEthereumMultipartyE2ESuite, sqlite3, erc20_erc721, true)	6m 37s
e2e-test (ethereum, evmconnect, TestEthereumMultipartyE2ESuite, postgres, erc20_erc721, true)	7m 43s
e2e-test (ethereum, evmconnect, TestEthereumMultipartyE2ESuite, sqlite3, erc1155, true)	6m 33s
e2e-test (ethereum, evmconnect, TestEthereumMultipartyTokensRemoteNameE2ESuite, postgres, erc20_e...	3m 37s
e2e-test (fabric, TestFabricE2ESuite, sqlite3, none, true)	3m 35s
e2e-test (ethereum, evmconnect, TestEthereumGatewayE2ESuite, sqlite3, erc20_erc721, false)	3m 24s
e2e-test (fabric, TestFabricGatewayE2ESuite, sqlite3, none, false)	4m 11s
e2e-test (ethereum, ethconnect, TestEthereumMultipartyE2ESuite, sqlite3, erc20_erc721, true)	6m 48s
e2e-test (ethereum, ethconnect, TestEthereumGatewayLegacyEthE2ESuite, sqlite3, erc1155, false)	2m 51s
	50m 27s

Provide feedback