use transifex for translations

.tx/config

@@ -0,0 +1,9 @@
+[main]
+host = https://www.transifex.com
+
+[android-password-store.main]
+file_filter = app/src/main/res/values-<lang>/strings.xml
+minimum_perc = 0
+source_file = app/src/main/res/values/strings.xml
+source_lang = en
+type = ANDROID

README.md

@@ -54,6 +54,10 @@ Ways to get in touch:
 
 - [Github issues](https://github.com/zeapo/Android-Password-Store/issues), use it if you have a bug report, you do not understand how something works or you want to submit a feature request.
 
+## Contributing Translations
+Interested in helping to translate Password Store? Contribute here:
+
+https://www.transifex.com/android-password-store/android-password-store/
 
 Libraries
 =========