fix: update nepali months data

[sajin-shrestha]

Description

This PR contains the updated month data from 2081 to 2099 based on the data from nepali patro.

Related Issue

#82

Type of Change

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• Bug fix
• New feature
• Enhancement
• Documentation update
• Refactor
• Other (please specify)

Checklist

• I have added/updated the necessary documentation on README.md.
• I have added appropriate test cases (if applicable) to ensure the changes are functioning correctly.
• My pull request has a clear title and description.

Additional Notes

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[aj3sh]

Thanks @sajin-shrestha for your contribution. 🙂

[aj3sh]

I checked the data with NepaliPatro, and the PR's data aligns with it. I have also confirmed the year's total days data using the below script:

function arraySum(numbers) {
  return numbers.reduce((sum, num) => sum + num, 0);
}

NP_MONTHS_DATA.forEach((data, i) => {
  if (arraySum(data[0]) !== data[1]) {
    console.log("Wrong Year's total days: " + (2000 + i));
  }
});