Prepare for release 21 (1.21) + add fastlane zh

Author: samuelchemla

app/build.gradle

@@ -22,8 +22,8 @@ android {
         vectorDrawables {
             useSupportLibrary true
         }
-        versionCode 20
-        versionName "1.20"
+        versionCode 21
+        versionName "1.21"
     }
 
     ksp {

fastlane/metadata/android/zh-CN/full_description.txt

@@ -0,0 +1,23 @@
+Synchronize images, videos, audio and downloads with your WebDAV server.
+Synchronize in both directions.
+Secure and open source.
+
+What is synchronized:
+* Images, video, screenshots that are displayed in your gallery will be synchronized. This includes images and videos in `DCIM/`, `Pictures/`, `Movies/` and `Download/`
+* If they are only available in a specific app but not in gallery, they won't be synchronized
+* Please note that messaging apps (messages, whatsapp, signal, etc.) generally offer you the choice between saving files in your gallery (in such case they will be synchronized) or not
+* All audio and music files that are visible in `Alarms/`, `Audiobooks/`, `Music/`, `Notifications/`, `Podcasts/`, `Ringtones/` and `Recordings/` will be synchronized
+* Beware that google's own voice recorder stores its files privately and offer its own cloud synchronization. They won't be synchronized by EasySync
+* All downloaded files in `Download/` will be synchronized, whether they are pdf, epubs, documents, images, etc.
+
+What is not synchronized:
+Everything not explicitly stated above is not synchronized. More specifically:
+* Applications
+* Applications data/state
+* Messages
+* Contacts
+* Games progress
+* Wifi or network parameters
+* Android settings and phone customization
+
+Files on **SD Card** are **NOT** synced

fastlane/metadata/android/zh-CN/images/icon.png

@@ -0,0 +1 @@
+Easy sync 会保持你的文件和 DAV 服务器间的同步状态

fastlane/metadata/android/zh-CN/images/phoneScreenshots/1_zh-CN.png

@@ -0,0 +1 @@
+EasySync