Configsuite-tui

Features
- Added user documentation
- Refined readme

Bug fixes
Fixed bug where the tui would not raise exceptions on config and schema errors when loading from cli

Features
- Induvidual widgets now show if their value is valid according to Config Suite or not
- Error messages from Config Suite now shows up in the description popup
Bug fixes
- Fix a bug where the TUI always would run in a sub process

Features
- Added a dialog to confirm when exiting application
- Add header to top of config file when saving file with the used schema name.
Schema can also be added manually. Should be formatted as: `! configsuite-tui: schema=<schema name>`
- Add possibility to pass config and schema from CLI
The use is as follows: `configsuite_tui <config file> -s/--schema <schema name>`
Config can also be written without option: `configsuite_tui <config file>`
If the config file has a schema name header, this will be loaded directly without having to specify schema in the CLI.

Features
- Fixed bugs where some exceptions was not caught when loading corrupt config file
- Changed to correct symbol for rendering a list
- Added possibility to quick save when a configuration already is loaded. This is done by double pressing Ctrl+S.

Features
- Removed possibility to load invalid or corrupt configuration file.