Final installation step missing note that OBS must be restarted for plugin to appear

[D4n2021]

Describe the bug
The windows installer currently doesn't mention the requirement to restart OBS (if it was running during the plugin-installation) to make the plugin appear.

To Reproduce
Steps to reproduce the behavior:

1. Launch OBS
2. Install plugin, finish installation
3. in OBS, go to the top menu bar and click on "Tools"
4. plugin is missing

Expected behavior
A clear and concise statement at the end of the installer procedure to inform the user of the required OBS restart