- Clearified build instructions (dependencies)
- Fixed gcovr instructions
- Clearified sanizier section.
- Updated installation instructions to be generator-independent.
- Removed coverage section, as it is already part of build instructions.

This was required, as clang-7 formatted code leads to
`compound-token-split-by-space` warning in clang-12.

- bump version to 0.2.0
- updated README.md
- added and updated several tests
- added and updated doc
- updated sample_extractor and added sample_executor
- added clang-format specification
- added support for sanitizers
- added more exhaustive gitlab-pipeline
- added more specific exceptions
- updated help-message generation in parsers (sub_parser, main_parser and basic_parser)
- minor improvements of CMakeLists.txt (e.g. added cppcheck)
- renamed full_example to large_example
- minor improvements to examples
- added test examples scripts
- added build_info_string
- unified arguments and options

- new exceptions based on clapp::exception::clapp_exception.
- added `parse_and_validate()` function.
- added found-func
- added help-option
- added more constexpr
- added more comments to examples
- code cleanup
- bump version t0 0.1.0
- added gitlab-ci pipeline
- added double/float values
- added support for vector of short/long options
- added doc-extractor