Merge pull request #9 from lukeea/patch-1

Update README.md: added Tutanota Calendar

README.md

@@ -112,6 +112,7 @@ These Firefox extensions can help prevent connections to Google domains and also
   - *Help requested!*
 - Calendar
   - [Lightning Calendar](https://www.thunderbird.net/en-US/calendar/) (Thunderbird)- Developed by Mozilla Foundation and open-source. Integrates into Thunderbird and SeaMonkey.
+  - [Tutanota Calendar](https://tutanota.com/calendar/) - Developed by Tutanota. Free cross-platform encrypted calendar. Allows importing of other Calendar files.
   - [Fruux](https://fruux.com/) - **14-eyes** - Open-source calendar using "sabre/dav" (open-source WebDAV, CardDAV, and CalDAV). They mention privacy quite a bit on their site. Very large number of features, and supports nearly every device: Windows, iOS, Linux, Android, BlackBerry, SailFish, and also a Webapp for browsers.
 - Docs/Sheets/Slides (cloud collaboration)
   - [CryptPad](https://cryptpad.fr/) - **9-eyes** - Open-source "zero knowledge" collaborative cloud editor. They offer Rich Text, Code, Presentation, Sheet (beta), Poll, Kanban, Whiteboard, and CryptDrive. 100% Client side encryption. Tons of useful features.