split config vs constants in deposit-contract spec

specs/phase0/deposit-contract.md

@@ -10,7 +10,7 @@
 
 - [Introduction](#introduction)
 - [Constants](#constants)
-  - [Contract](#contract)
+- [Configuration](#configuration)
 - [Ethereum 1.0 deposit contract](#ethereum-10-deposit-contract)
   - [`deposit` function](#deposit-function)
     - [Deposit amount](#deposit-amount)
@@ -27,14 +27,23 @@ This document represents the specification for the beacon chain deposit contract
 
 ## Constants
 
-### Contract
+The following values are (non-configurable) constants used throughout the specification.
+
+| Name | Value |
+| - | - |
+| `DEPOSIT_CONTRACT_TREE_DEPTH` | `2**5` (= 32) |
+
+## Configuration
+
+*Note*: The default mainnet configuration values are included here for spec-design purposes.
+The different configurations for mainnet, testnets, and YAML-based testing can be found in the [`configs/constant_presets`](../../configs) directory.
+These configurations are updated for releases and may be out of sync during `dev` changes.
 
 | Name | Value |
 | - | - |
 | `DEPOSIT_CHAIN_ID` | `1` |
 | `DEPOSIT_NETWORK_ID` | `1` |
 | `DEPOSIT_CONTRACT_ADDRESS` | **TBD** |
-| `DEPOSIT_CONTRACT_TREE_DEPTH` | `2**5` (= 32) |
 
 ## Ethereum 1.0 deposit contract