quick fix child hotkey stake threshold (#126)

* wip

* wip

Author: MichaelTrestman

docs/validators/child-hotkeys.md

@@ -50,8 +50,6 @@ See the above diagram. With the child hotkeys, if an attacker steals a child hot
   The terms "child hotkey" and "parent hotkey" are only terms of convenience. There is nothing inherently different about a "child hotkey" that separates it from a "parent hotkey". Neither have any special attributes compared to a normal hotkey.
   :::
 
----
-
 ## Features
 
 The child hotkey features are as follows:
@@ -71,18 +69,21 @@ The following rate limits apply for child hotkeys:
 
 See [Rate Limits in Bittensor](../learn/chain-rate-limits.md).
 
-## Minimum stake
+## Minimum stake requirement
 
-The minimum stake you can redelegate to a child hotkey is as follows:
+To set child hotkeys, the parent hotkey must have a minimum total stake. This requirement checks the TAO-equivalent value of your alpha stake across all subnets.
 
-- **Testnet**: 100 testnet ALPHA.
-- **Mainnet**: 1000 ALPHA.
+The minimum stake requirement is:
 
----
+- **Mainnet**: 1000 TAO worth of alpha
+- **Testnet**: 100 TAO worth of alpha
 
-## Installing
+**How it's calculated**: Your alpha stake is summed **across ALL subnets** (not just the subnet where you're setting children). Each subnet's alpha is converted to TAO value using that subnet's alpha price, then all values are summed together. View [source code](https://github.com/opentensor/subtensor/blob/main/pallets/subtensor/src/staking/helpers.rs#L47-L62).
+
+:::tip
+Query `subtensorModule.stakeThreshold()` to check the current threshold.
+:::
 
-This feature is available in Bittensor 7.4.0 and later versions. See [Install Bittensor](../getting-started/installation.md).
 
 ## Child hotkey commands