Allow user to control what happens to pinned tabs

- 1.2.1
- Skipping pinned tabs from being saved: being pinned, the browser will keep them around already
- Update info texts, including the fact that Microsoft Edge is now supported as well: just use the Google Chrome store to install the extension

Version 1.2.0 brings a most requested auto-save feature, that will backup your open tabs taking periodic snapshots and storing them as bookmarks.

Auto-save requires additional permissions, in particular:
- alarms, so that we can trigger the periodic save routing
- storage, so that we can save the settings required for the auto-save functionality

Lot of work behind the scenes to make it better, and more expandable in the future. Please, keep using the GitHub page to let me know of issues, and feature requirements.

Best regards,
Salvatore

1.2.0
- Partially address enhancement #1 Option to set autosave and autodelete old saves.
- Upgrade Bootstrap CSS library to v4.4.1
- Upgrade webextension-polyfill to v0.6.0
- Manifest updates to include additional permissions (alarms, storage), background scripts, and options_ui
- UI cosmetic and usability enhancements

Version 1.1.0 provides one enhancement and one bugfix, both reported by user. Also minor cosmetic enhancement. Here the list:

- Enhancement: selecting an existing folder to save bookmarks into used to delete all the preexisting bookmarks in that folder. That default behavior has been changed to *append*. Option has been provided to user for cases where *replace all* is desired.
- BugFix: pages with same tab title but different URL would not be saved correctly. That has been fixed now.
- Cosmetic: release version has been added to the bottom of the popup.

Fixed homepage in manifest.json