Merge glTF scene rendering sample (#744)

* Started reworking the scene rendering to sample
Use glTF instead of ASSIMP, per-material pipelines, material loading, etc.

* Visibility toggle for scene nodes

* Fixed lighting, updated GLSL and HLSL shaders

* Renamed sample

* Code-Cleanup, comments, validation fixes

* Android build

* Started on tutorial for glTF scene rendering sample

* Minor code cleanup

* Adding new chapters to the tutorial for glTF scene rendering sample

* Added info on normal map shader bindings, spelling

* Added drawing chapter

* Getter for texture descriptors

Makes code a easier to read

* Renamed glTF scene sample

* Add markdown files to projects

* Updated readme, separate chapter for glTF samples

* Comments

* Removed unused screenshot

android/examples/scenerendering/build.gradle

@@ -1,66 +0,0 @@
-apply plugin: 'com.android.application'
-apply from: '../gradle/outputfilename.gradle'
-
-android {
-    compileSdkVersion 26
-    defaultConfig {
-        applicationId "de.saschawillems.vulkanScenerendering"
-        minSdkVersion 19
-        targetSdkVersion 26
-        versionCode 1
-        versionName "1.0"
-        ndk {
-            abiFilters "armeabi-v7a"
-        }
-        externalNativeBuild {
-            cmake {
-                cppFlags "-std=c++14"
-                arguments "-DANDROID_STL=c++_shared", '-DANDROID_TOOLCHAIN=clang'
-            }
-        }
-    }
-    sourceSets {
-        main.assets.srcDirs = ['assets']
-    }
-    buildTypes {
-        release {
-            minifyEnabled false
-            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
-        }
-    }
-    externalNativeBuild {
-        cmake {
-            path "CMakeLists.txt"
-        }
-    }
-}
-
-task copyTask {
-    copy {
-        from '../../common/res/drawable'
-        into "src/main/res/drawable"
-        include 'icon.png'
-    }
-
-    copy {
-        from '../../../data/shaders/glsl/base'
-        into 'assets/shaders/glsl/base'
-        include '*.spv'
-    }
-
-    copy {
-       from '../../../data/shaders/glsl/scenerendering'
-       into 'assets/shaders/glsl/scenerendering'
-       include '*.*'
-    }
-
-    copy {
-       from '../../../data/models/sibenik'
-       into 'assets/models/sibenik'
-       include '*.*'
-    }
-
-
-}
-
-preBuild.dependsOn copyTask