Add enable internal mode tasks and gifs

introductionSection/section-info.yaml

@@ -1,3 +1,4 @@
 custom_name: Introduction
 content:
   - welcomeLesson
+  - setupLesson

introductionSection/setupLesson/internalModeSetupTask/src/main/kotlin/org/jetbrains/academy/plugin/course/dev/setup/Main.kt

@@ -0,0 +1,5 @@
+package org.jetbrains.academy.plugin.course.dev.setup
+
+fun main() {
+
+}

introductionSection/setupLesson/internalModeSetupTask/task-info.yaml

@@ -0,0 +1,5 @@
+type: theory
+custom_name: Enable Internal Mode
+files:
+  - name: src/main/kotlin/org/jetbrains/academy/plugin/course/dev/setup/Main.kt
+    visible: false

introductionSection/setupLesson/internalModeSetupTask/task-remote-info.yaml

@@ -0,0 +1 @@
+id: 853483765

introductionSection/setupLesson/internalModeSetupTask/task.md

@@ -0,0 +1,12 @@
+To have access to some internal actions you need to enable `Internal Mode`.
+Please, follow steps in internal mode instruction configuration [by this link](https://plugins.jetbrains.com/docs/intellij/enabling-internal.html) and enable it in your IDE.
+
+![Internal mode documentation](./../../../common/src/main/resources/images/internal-mode-doc.gif)
+
+**Do not forget to restart you IDE after changing idea.properties file!!!**
+
+Also, following gif will show you how Helena done this in her IDE.
+
+![Internal mode documentation](./../../../common/src/main/resources/images/internal-mode-ide.gif)
+
+

introductionSection/setupLesson/lesson-info.yaml

@@ -0,0 +1,3 @@
+custom_name: Setup before you start
+content:
+  - internalModeSetupTask