v0.28.0

Added

• Extended WorkoutData with new methods: best_intervals, best_distance_intervals, fastest_distance_intervals, and elevation_gain for easier access to interval and elevation metrics.
• Added fastest_distance_interval and multiple_fastest_distance_intervals functions for finding the fastest intervals over fixed distances.
• Added new elevation-related functions: elevation_gain, elevation_smooth_time, and elevation_smooth for calculating and smoothing elevation data.
• Added new grade-related functions: grade_smooth_time, grade_smooth, and grade_raw for calculating smoothed and raw grade (slope) values.
• WorkoutData now automatically computes a new time column containing the relative time (in seconds) since the workout started, in addition to the datetime index.
• WorkoutData now automatically adds an is_moving column based on the speed column.
• WorkoutData now automatically computes and adds a grade column if both distance and elevation are present.

Changed

• best_interval and multiple_best_intervals now return a dictionary with the max mean value and the start/stop indices of the best interval for a provided time window or list of time windows, for consistency with distance-based interval functions.