Proposal for OpenHarmony Adaptation of [ Fraction.js ]

# Title: Proposal for OpenHarmony Adaptation of [ Fraction.js ] ## Background OpenHarmony is an open-source operating system and community that is widely used in the field of intelligent terminals. Currently, Fraction.js is extensively utilized in the mobile application development domain of OpenHarmony. In order to enable Fraction.js to support the OpenHarmony system, we have modified some of the code of Fraction.js. We plan to submit the modified code to the Fraction.js community. The purpose of creating this Issue is to initiate discussions with the community. We sincerely welcome you to put forward your valuable suggestions. ## Adaptation Proposal We have completed the OpenHarmony adaptation for Fraction.js, including: - Using OpenHarmony cross-compile tools build Fraction.js. - Adding OpenHarmony guide to help developers to use Fraction.js. We're willing to make a contribution by adding instructions specific to OpenHarmony for using Fraction.js. We will submit the changes via a Pull Request(PR) shortly. ## Testing Results We have conducted extensive compatibility testing across: - DevEco Studio 5.0.3 Release-5.0.9.221, SDK: API15 (OpenHarmony 5.0.3.135) - DevEco Studio 5.0.4 Beta1-5.0.9.320, SDK: API16 (OpenHarmony 5.0.4.150) - DevEco Studio 5.0.3 Release-5.0.9.300, SDK: API15 (OH_SDK 5.0.3.135(SP1)) - DevEco Studio 5.0.4 Beta1 5.0.9.320, SDK: API16 (OH SDK 5.0.4.150) ## Labels compatibility, cross-platform