How to launch README file when the plugin is installed for first time to instruct the user?
messages.json in the plugin’s root folder and add a
"install" key in it.
How to make sure it that Readme file should be shown only when user installs the plugin ?
That’s what it’s for…
You mean to say that
"install" is the key which will handle this use case ?
Yes. That’s what it’s for…
if you have further question, read the really short doc first then.