- Added an options page (accessible on about:addons -> Extensions -> Click on Lap Clipboard Inserter -> Preferences) to change the interval that the clipboard is read.
Due to this change, the extension now requires the "storage" permission to save the current settings. If the default setting is being used (300 ms), then it won't save anything.

- Fixed console.error on tabs querying occupying multiple lines to print the error.
- Complied to the linter (eslint) complaints.
- Renamed icons/LICENSE to icons/ATTRIBUTION.
- Changed the manifest.json description.