GC-45: Update copyright information:

- Changes to code base were previously done in 2020 as well (based on
git history).

Noticket: Small improvements to documentation:

- List supported Python versions a bit more explicitly (improves
readibility/stands out better).
- Use dashes instead of asterisks for lists of items (just a syntax
change).
- Added link to documentation (RTD) to README file.

GC-2: Added basic development documentation:

- Documented development environment set-up.
- Documented how to run the tests.
- Documented how to build documentation.

GC-2: Adding initial documentation skeleton with some basic information about the project:

- Added basic documentation describing the project.
- Updated gitignore file to ensure documentation build artifacts stay
out of the repository.
- README file placed at top directory for convenient access.