Update cairo-and-sierra.adoc

Author: LandauRaz

components/Starknet/modules/architecture-and-concepts/pages/smart-contracts/cairo-and-sierra.adoc

@@ -1,7 +1,7 @@
 [id="sierra"]
 = Sierra
 
-== Introduction
+== Overview
 
 Before Starknet Alpha v0.11.0, developers would write contracts in an old version of Cairo, now termed Cairo 0, compile them locally to xref:why_do_we_need_casm[_Casm_], and submit the compilation output to the Starknet sequencer for execution. Starting from the current version of Cairo (previously termed Cairo 1) introduced in Starknet Alpha v0.11.0, the compilation output resulting of Cairo contracts does *not* include Casm. Instead, it includes instructions in an intermediate representation called xref:why_do_we_need_sierra[_Sierra_]. This new contract class is then compiled by the sequencer, via a Sierra-to-Casm compiler, to generate the Casm associated with this class.
 
@@ -79,4 +79,4 @@ Smart contracts written with Cairo cannot contain user defined hints. This is al
 determined by the Sierra-to-Casm compiler. Since this compilation is there to ensure that only
 "safe" Casm is generated, there is no room for hints that are not generated by the compiler.
 
-In the future, Cairo may include hint syntax similar to Cairo 0, but in any case it will not be available for smart contracts deployed on Starknet (instead, https://medium.com/starkware/fractal-scaling-from-l2-to-l3-7fe238ecfb4f[L3s^] on top of Starknet may make use of such functionality). Note that this is currently not part of Starknet's roadmap.
+In the future, Cairo may include hint syntax similar to Cairo 0, but in any case it will not be available for smart contracts deployed on Starknet (instead, https://medium.com/starkware/fractal-scaling-from-l2-to-l3-7fe238ecfb4f[L3s^] on top of Starknet may make use of such functionality). Note that this is currently not part of Starknet's roadmap.