Add FAQ about custom SSLSocketFactory

README.md

@@ -101,6 +101,12 @@ compile 'io.tus.android.client:tus-android-client:0.1.8'
 
 The documentation of the latest version (master branch of git repository) can be found online at [tus.github.io/tus-android-client/javadoc/](https://tus.github.io/tus-android-client/javadoc/).
 
+## FAQ
+
+### I get TLS/SSL errors on older Android versions!
+
+On devices running Android 4.4 earlier, errors can appear during the SSL handshake. This is caused by wrong behavior inside the platform and can be fixed by providing a custom `SSLSocketFactory` as described in https://stackoverflow.com/a/30302235 and https://github.com/tus/tus-java-client/blob/master/README.md#can-i-use-my-own-custom-sslsocketfactory. More details are also available at https://github.com/tus/tus-java-client/issues/14#issuecomment-402786097.
+
 ## License
 
 MIT