Added initial XML template

Used context argument in switch_message()

Added LaTeX templates ...

This required adding a separate Jinja2 environment, because LaTeX syntax
is incompatible with Jinja2.

Fully implemented --end-of-week/-e switch ...

(was --week-offset/-w)

Added initial code for --week-offset CLI switch

Preliminary code to refactor CLI error messages

Reimplemented text output using Jinja2 templates

Initialisation of ignored CLI args moved to cli.py

Added basic plain text output

Fixed incorrect raising of PaperError

Added calendar initialisation via configuration

Renamed week() to make_week()

Major revamp of configuration handling ...

• Moved configuration file loading into Configuration class.
• Added config getter methods to Configuration.
• Updated and extended custom exception types.
• Restructured error handling.
• Factored out app name.

Fixed broken “offsets” for INFO202/S2

Deleted obsolete comment

Converted load_config() into Configuration class

Removed reference to PROG constant

Moved load_config() into config.py

Added configuration defaults ...

The app nows looks for configuration in ~/.config if no configuration
file is explicitly specified. If the default configuration isn’t found,
a default configuration file is copied into ~/.config.

Refactored program name

Renamed module

Removed redundant #! line

Rearranged calendar code into sub-package

Split off errors & resolved import issues

Fixed unresolved imports ...

Figured out the correct magic sprinkles 🙄.

Modularised more config-related code

Moved CLI arg processing into config package

Restructured app as a package hierarchy ...

• main.py → app.py
• Added config and templates sub-packages.
• config.yml → package resource default.yml

Added core prototype of new date generation script

Updated README ...

• Cleaned up Markdown.
• Added some introductory text.