I am new to add-on development. I would like to know where to find the translations for name and description text of my add-on.
Essentially under whatever name you want in a messages.json file. See https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/Internationalization#Internationalizing_manifest.json
Thanks for the link. But, where can I find the the translations ( message.json content) for different languages?
You have to create the translation files yourself. And then you will obviously find them wherever you saved them (which should be where the linked documentation tells you to).
Exactly, see a couple sections before the one I linked: https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/Internationalization#Providing_localized_strings_in__locales