Consider asking for a restart, if really required

[oliviercailloux]

Many VSCode extensions work without restart. Please attempt to make this one work without restart.

If a restart is required, please let the user know it. There is a mechanism for this in VSCode, I think, as I have already seen one extension asking for this (VSCode prompt just after installation).

Currently, it is misleading: VSCode will indicate that the extension is enabled, just after install, and before restart, even though it seems to work only after restart (at least, it started working only after restart in my case).