added stone/eth (#485)

Author: aditya520

pages/price-feeds/sponsored-feeds/evm.mdx

@@ -50,6 +50,7 @@ Update Parameters: **1 hour heartbeat or 1% price deviation**
 | ---------- | ------------------------------------------------------------------ |
 | wUSDM/USDM | `3d392a0fc3ae7fac4d6ba15e99a4c2bec2debbe1c9fc7d950ec0972ee716f559` |
 | USDM/USD   | `a6a0dfa49b6b3a93510658245618099f5e842514970f596cf64fad9e0d658193` |
+| STONE/ETH  | `7a508a94c9276cbc60d04e1a8cf839d20d835bb869a74487dfffa8f1bfd1ce42` |
 
 ## Optimism Sepolia