also:
- added `toml_version.h`
- added version number to toml.hpp
- added `node::visit()`
- added `table::empty()`
- added `array::empty()`
- added version number to `toml.hpp`
- added ostream operator overload for `source_position`
- added tests for string escape sequences
- added tests for + in bare keys (toml/issues/687)
- added tests for hexfloat literals (toml/issues/562)
- added c++20 char8_t detection to meson
- moved third party submodules to `/extern`
- refactored noexcept version of `parse_result` to be more useful
- refactored all code to 'mostly' stick to a 120 column limit
- fixed some minor stuff picked up by gcc9
new file: .editorconfig
new file: .gitattributes
new file: .gitignore
new file: .gitmodules
new file: LICENSE
new file: README.md
new file: examples/example.cpp
new file: examples/example.toml
new file: examples/meson.build
new file: include/toml++/toml.h
new file: include/toml++/toml_array.h
new file: include/toml++/toml_common.h
new file: include/toml++/toml_formatter.h
new file: include/toml++/toml_node.h
new file: include/toml++/toml_node_view.h
new file: include/toml++/toml_parser.h
new file: include/toml++/toml_table.h
new file: include/toml++/toml_utf8.h
new file: include/toml++/toml_utf8_generated.h
new file: include/toml++/toml_value.h
new file: meson.build
new file: python/ci_single_header_check.py
new file: python/generate_single_header.py
new file: python/generate_unicode_functions.py
new file: tests/catch2
new file: tests/catch2.h
new file: tests/lifetimes.cpp
new file: tests/main.cpp
new file: tests/meson.build
new file: tests/parsing_arrays.cpp
new file: tests/parsing_booleans.cpp
new file: tests/parsing_comments.cpp
new file: tests/parsing_dates_and_times.cpp
new file: tests/parsing_floats.cpp
new file: tests/parsing_integers.cpp
new file: tests/parsing_key_value_pairs.cpp
new file: tests/parsing_spec_example.cpp
new file: tests/parsing_strings.cpp
new file: tests/parsing_tables.cpp
new file: tests/tests.cpp
new file: tests/tests.h
new file: toml.hpp
new file: vs/.runsettings
new file: vs/example.vcxproj
new file: vs/test_char.vcxproj
new file: vs/test_char8.vcxproj
new file: vs/test_char8_noexcept.vcxproj
new file: vs/test_char_noexcept.vcxproj
new file: vs/test_strict_char.vcxproj
new file: vs/test_strict_char8.vcxproj
new file: vs/test_strict_char8_noexcept.vcxproj
new file: vs/test_strict_char_noexcept.vcxproj
new file: vs/toml++.natvis
new file: vs/toml++.props
new file: vs/toml++.sln
new file: vs/toml++.vcxproj
new file: vs/toml++.vcxproj.filters
