fix typo

Author: wackerow

src/content/smart-contracts/index.md

@@ -6,7 +6,7 @@ lang: en
 
 # Introduction to smart contracts {#introduction-to-smart-contracts}
 
-Smart contract are the fundamental building blocks of Ethereum's application layer. They are computer programs stored on the blockchain that follow "if this then that" logic, and are guaranteed to execute according to the rules defined by its code, which cannot be changed once created.
+Smart contracts are the fundamental building blocks of Ethereum's application layer. They are computer programs stored on the blockchain that follow "if this then that" logic, and are guaranteed to execute according to the rules defined by its code, which cannot be changed once created.
 
 Nick Szabo coined the term "smart contract". In 1994, he wrote [an introduction to the concept](https://www.fon.hum.uva.nl/rob/Courses/InformationInSpeech/CDROM/Literature/LOTwinterschool2006/szabo.best.vwh.net/smart.contracts.html), and in 1996 he wrote [an exploration of what smart contracts could do](https://www.fon.hum.uva.nl/rob/Courses/InformationInSpeech/CDROM/Literature/LOTwinterschool2006/szabo.best.vwh.net/smart_contracts_2.html).