Command: Open settings

[nelsam]

Description

When a user wants to edit their config, they should be able to easily open the config files without necessarily knowing where they are located.

Follow-up for #15

Expected behavior

I can open the config files without knowing their exact location.

Actual behavior

I need to know the config files' location to edit them.

Subtasks

• I can open my project list with a single command
• I can open the main settings file with a single command
• There is a UI showing the config files that vidar is reading from
  • I can navigate these files with the keyboard
  • I can navigate these files with the mouse