fix for document build

Full Changelog: 1.0.3...1.0.4

Documentation deploy to gh-page

Full Changelog: 1.0.2...1.0.3

better Fraction

try to avoid overflow using gcd() to extract the common factors.

make vscode-friendly

known issue:

MacOS does not work with C++20's concepts

initial release

passed all checks of github actions

for preparation only

0.1

Initial commit