Merge pull request #31 from pyth-network/doc

Point reader to function variants in readme

Author: jayantk

README.md

@@ -39,6 +39,9 @@ contract ExampleContract {
         pyth.updatePriceFeeds{value: fee}(priceUpdateData);
 
         bytes32 priceID = 0xf9c0172ba10dfa4d19088d94f5bf61d3b54d5bd7483a322a982e1373ee8ea31b;
+	// Read the current value of priceID, aborting the transaction if the price has not been updated recently.
+	// Every chain has a default recency threshold which can be retrieved by calling the getValidTimePeriod() function on the contract.
+	// Please see IPyth.sol for variants of this function that support configurable recency thresholds and other useful features.
         return pyth.getPrice(priceID);
     }
 }