Add missing description for feature switch (#19428)

sdk/src/feature_set.rs

@@ -213,6 +213,7 @@ lazy_static! {
         (add_missing_program_error_mappings::id(), "add missing program error mappings"),
         (system_transfer_zero_check::id(), "perform all checks for transfers of 0 lamports"),
         (dedupe_config_program_signers::id(), "dedupe config program signers"),
+        (verify_tx_signatures_len::id(), "prohibit extra transaction signatures"),
         (vote_stake_checked_instructions::id(), "vote/state program checked instructions #18345"),
         (updated_verify_policy::id(), "Update verify policy"),
         (neon_evm_compute_budget::id(), "bump neon_evm's compute budget"),