add DebugBlock and DebugAddress config comments

Author: magicxyyz

params/config_arbitrum.go

@@ -63,8 +63,8 @@ type ArbitrumChainParams struct {
 	MaxCodeSize               uint64          `json:"MaxCodeSize,omitempty"`     // Maximum bytecode to permit for a contract. 0 value implies params.DefaultMaxCodeSize
 	MaxInitCodeSize           uint64          `json:"MaxInitCodeSize,omitempty"` // Maximum initcode to permit in a creation transaction and create instructions. 0 value implies params.DefaultMaxInitCodeSize
 	MaxUncompressedBatchSize  uint64          `json:"MaxUncompressedBatchSize,omitempty"`
-	DebugBlock                uint64          `json:"DebugBlock,omitempty"`
-	DebugAddress              *common.Address `json:"DebugAddress,omitempty"`
+	DebugBlock                uint64          `json:"DebugBlock,omitempty"`   // block number of the injected debug block
+	DebugAddress              *common.Address `json:"DebugAddress,omitempty"` // address of the debug account to be pre-funded in during debug block
 }
 
 func (c *ChainConfig) IsArbitrum() bool {