enhance implicit conversions section

bishabosha · bishabosha · commit f2c90e327b79 · 2022-11-09T11:57:58.000+01:00
diff --git a/_tour/implicit-conversions.md b/_tour/implicit-conversions.md
@@ -10,6 +10,11 @@ previous-page: implicit-parameters
 redirect_from: "/tutorials/tour/implicit-conversions.html"
 ---
 
+Implicit conversions are a powerful Scala feature that enable two common use cases:
+- allow users to supply an argument of one type, as if it were another type, to avoid boilerplate.
+- to provide additional members to closed classes (replaced by [extension methods][exts] in Scala 3).
+
+### Detailed Explanation
 {% tabs implicit-conversion-defn class=tabs-scala-version %}
 {% tab 'Scala 2' %}
 In Scala 2, an implicit conversion from type `S` to type `T` is defined by an [implicit value]({% link _tour/implicit-parameters.md %}) which has function type `S => T`, or by an implicit method convertible to a value of that type.
@@ -33,7 +38,11 @@ In the second case, a conversion `c` is searched for, which is applicable to `e`
 
 An example is to compare two strings `"foo" < "bar"`. In this case, `String` has no member `<`, so the implicit conversion `Predef.augmentString("foo") < "bar"` is inserted. (`scala.Predef` is automatically imported into all Scala programs.)
 
-**Beware the power of implicit conversions:**
+### How are implicit conversions selected?
+
+See this [Scala FAQ Answer](https://docs.scala-lang.org/tutorials/FAQ/index.html#where-does-scala-look-for-implicits).
+
+### Beware the power of implicit conversions
 
 {% tabs implicit-conversion-warning class=tabs-scala-version %}
 {% tab 'Scala 2' %}
@@ -59,3 +68,5 @@ To turn off the warnings take either of these actions:
 - Invoke the compiler with `-language:implicitConversions`
 {% endtab %}
 {% endtabs %}
+
+[exts]: {% link _overviews/scala3-book/ca-extension-methods.md %}
