Fix relative dates not working

fix: Time for relative dates #24

Fix date-time parsing and first start

• Fix: Parse time correctly if after 8pm
• Fix: Avoid error on first start

Add support for listing all open tasks; fix configuration errors; fix close task

• Use cuo to list all tasks that are due (or overdue) until end of today.
• Fixes errors when completing task via ⌥+Enter
• Fixes configuration errors configuration if Folder Id is not specified

Fix validation error

fix: Validation of Folder Id #16

Assign tasks to yourself by default

• Feature: By default assign tasks yourself (so they appear in your Inbox)
• Fix: cu:config validate is now working again

Add support for natural language when specifying due date

Due dates can now also be specified via '@' and:

• mon or monday Task is due for next Monday (same for other days)
• tod or today Task is due for today
• tom or tomorrow Task is due for tomorrow
• 2020-12-31 Task is due on 2020-12-31 at the current time
• 2020-12-31 14.00 Task is due on 2020-12-31 at 2pm (note: Hours, minutes and seconds are separated via ., as : is used to define the task's description)
• 14.00 Task is due today at 2pm (note: Hours, minutes and seconds are separated via ., as : is used to define the task's description)

Allow no due date for tasks

• Allow no due date for tasks (no auto-date)
• Fix search not working without configured hierarchy levels

Fix for API key storage

Fixes storing API key in configuration

Fix for due date

• Fixes debug log output
• Fixes due date being incorrect in ClickUp

Update terminology in settings

• Updated terminology used in cu:config to ClickUp2.0