Merge pull request #15267 from rhumbertgz/patch-1

Add missing article and preposition

Author: nicolasstucki

docs/_docs/reference/overview.md

@@ -45,7 +45,7 @@ These constructs replace existing constructs with the aim of making the language
 - [Extension methods](contextual/extension-methods.md)
   replace implicit classes with a clearer and simpler mechanism.
 - [Opaque type aliases](other-new-features/opaques.md)
-  replace most uses of value classes while guaranteeing absence of boxing.
+  replace most uses of value classes while guaranteeing the absence of boxing.
 - [Top-level definitions](dropped-features/package-objects.md)
   replace package objects, dropping syntactic boilerplate.
 - [Export clauses](other-new-features/export.md)
@@ -131,7 +131,7 @@ These are additions to the language that make it more powerful or pleasant to us
 
 ## Metaprogramming
 
-The following constructs together aim to put metaprogramming in Scala on a new basis. So far, metaprogramming was achieved by a combination of macros and libraries such as [Shapeless](https://github.com/milessabin/shapeless) that were in turn based on some key macros. Current Scala 2 macro mechanisms are a thin veneer on top the current Scala 2 compiler, which makes them fragile and in many cases impossible to port to Scala 3.
+The following constructs together aim to put metaprogramming in Scala on a new basis. So far, metaprogramming was achieved by a combination of macros and libraries such as [Shapeless](https://github.com/milessabin/shapeless) that were in turn based on some key macros. Current Scala 2 macro mechanisms are a thin veneer on top of the current Scala 2 compiler, which makes them fragile and in many cases impossible to port to Scala 3.
 
 It's worth noting that macros were never included in the [Scala 2 language specification](https://scala-lang.org/files/archive/spec/2.13/) and were so far made available only under an `-experimental` flag. This has not prevented their widespread usage.