[Contract dev > Techniques > Estimate gas usage in TON contracts] link to a carry-value pattern page

 Link to a carry-value pattern page here, when it's merged: 

```
<Aside type="tip">
  The following explanation uses an abstract contract system and is not connected to 
  any existing project. It is primarily applicable to systems that follow **a carry-value 
  pattern,**  where value is passed between contracts as part of message processing.
</Aside>
```