mnt 1.4

• Added a NEWS.md file to track changes to the package.
• Added Pearson and Johnson four-moment approximations for BHEP critical values.
• Added p-values for all three calibration methods, returned as pvalue.
• Monte Carlo remains the default calibration method.
• Updated the result printer to display the calibration method and p-value.
• Added numerical safeguards for calculating limiting moments and fitting Johnson distributions.