add documentation for scala3-migrate in the migration guide (#2289)

* add documentation for scala3-migrate in the migration guide

* fix some code reviews

Author: mlachkar

_overviews/scala3-migration/incompat-contextual-abstractions.md

@@ -2,7 +2,7 @@
 title: Contextual Abstractions
 type: section
 description: This chapter details all incompatibilities caused by the redesign of contextual abstractions
-num: 17
+num: 18
 previous-page: incompat-dropped-features
 next-page: incompat-other-changes
 ---

_overviews/scala3-migration/incompat-dropped-features.md

@@ -2,7 +2,7 @@
 title: Dropped Features
 type: section
 description: This chapter details all the dropped features
-num: 16
+num: 17
 previous-page: incompat-syntactic
 next-page: incompat-contextual-abstractions
 ---

_overviews/scala3-migration/incompat-other-changes.md

@@ -2,7 +2,7 @@
 title: Other Changed Features
 type: section
 description: This chapter details all incompatibilities caused by changed features
-num: 18
+num: 19
 previous-page: incompat-contextual-abstractions
 next-page: incompat-type-checker
 ---

_overviews/scala3-migration/incompat-syntactic.md

@@ -2,7 +2,7 @@
 title: Syntactic Changes
 type: section
 description: This chapter details all the incompatibilities caused by syntactic changes
-num: 15
+num: 16
 previous-page: incompatibility-table
 next-page: incompat-dropped-features
 ---

_overviews/scala3-migration/incompat-type-checker.md

@@ -2,7 +2,7 @@
 title: Type Checker
 type: section
 description: This chapter details the unsoundness fixes in the type checker
-num: 19
+num: 20
 previous-page: incompat-other-changes
 next-page: incompat-type-inference
 ---

_overviews/scala3-migration/incompat-type-inference.md

@@ -2,7 +2,7 @@
 title: Type Inference
 type: section
 description: This chapter details the incompatibilities caused by the new type inference algorithm
-num: 20
+num: 21
 previous-page: incompat-type-checker
 next-page: options-intro
 ---

_overviews/scala3-migration/incompatibility-table.md

@@ -2,7 +2,7 @@
 title: Incompatibility Table
 type: chapter
 description: This chapter list all the known incompatibilities between Scala 2.13 and Scala 3 
-num: 14
+num: 15
 previous-page: tooling-syntax-rewriting
 next-page: incompat-syntactic
 ---

_overviews/scala3-migration/options-intro.md

@@ -2,7 +2,7 @@
 title: Compiler Options
 type: chapter
 description: This chapter shows the difference between Scala 2.13 and Scala 3 compiler options
-num: 21
+num: 22
 previous-page: incompat-type-inference
 next-page: options-lookup
 ---

_overviews/scala3-migration/options-lookup.md

@@ -2,7 +2,7 @@
 title: Compiler Options Lookup Table
 type: section
 description: This section contains the compiler options lookup tables
-num: 22
+num: 23
 previous-page: options-intro
 next-page: options-new
 ---

_overviews/scala3-migration/options-new.md

@@ -2,7 +2,7 @@
 title: New Compiler Options
 type: section
 description: This chapter lists all the new compiler options in Scala 3
-num: 23
+num: 24
 previous-page: options-lookup
 next-page: scaladoc-settings-compatibility
 ---

_overviews/scala3-migration/plugin-intro.md

@@ -2,7 +2,7 @@
 title: Compiler Plugins
 type: chapter
 description: This section shows how to migrate from using Scala 2 compiler plugins
-num: 25
+num: 26
 previous-page: options-new
 next-page: plugin-kind-projector
 ---

_overviews/scala3-migration/plugin-kind-projector.md

@@ -2,7 +2,7 @@
 title: Kind Projector Migration
 type: section
 description: This section shows how to migrate from the kind-projector plugin to Scala 3 kind-projector syntax
-num: 26
+num: 27
 previous-page: plugin-intro
 next-page: external-resources
 ---