Does Liferay provide a service or route for loading translation JSON from a portlet for example?
No. Liferay generally uses
Lanaguage_xx.properties files. There's no tool to convert a JSON object into Language.properties files. However, if you're writing your own portlet, you can always look up your localization in the JSON object if you want. You'll just have to write all the code for this yourself.
Where's we can keep localisations for all Liferay instance?
You should keep your localization/translations in your portlet. This way, when you deploy your portlet, all the necessary translations will be present.
