Added monetization tutorial and added tutorial descriptions.

...formplayer/fragment/mainactivity/main/TutorialFragment.kt

.../futo/platformplayer/views/behavior/GestureControlView.kt

...ava/com/futo/platformplayer/views/pills/WidePillButton.kt

...va/com/futo/platformplayer/views/video/FutoVideoPlayer.kt

app/src/main/res/drawable/background_pill_description.xml

app/src/main/res/layout/view_gesture_controls.xml

app/src/main/res/layout/view_wide_pill_button.xml

app/src/main/res/values/strings.xml

app/src/main/res/values/wide_pill_button_attrs.xml