Finetune aggregate_temporal_period description

[soxofaan]

openeo-processes/aggregate_temporal_period.json

Line 21 in 0dd3ab0

"description": "The time intervals to aggregate. The following pre-defined values are available:\n\n* `hour`: Hour of the day\n* `day`: Day of the year\n* `week`: Week of the year\n* `dekad`: Ten day periods, counted per year with three periods per month (day 1 - 10, 11 - 20 and 21 - end of month). The third dekad of the month can range from 8 to 11 days. For example, the fourth dekad is Feb, 1 - Feb, 10 each year.\n* `month`: Month of the year\n* `season`: Three month periods of the calendar seasons (December - February, March - May, June - August, September - November).\n* `tropical-season`: Six month periods of the tropical seasons (November - April, May - October).\n* `year`: Proleptic years\n* `decade`: Ten year periods ([0-to-9 decade](https://en.wikipedia.org/wiki/Decade#0-to-9_decade)), from a year ending in a 0 to the next year ending in a 9.\n* `decade-ad`: Ten year periods ([1-to-0 decade](https://en.wikipedia.org/wiki/Decade#1-to-0_decade)) better aligned with the anno Domini (AD) calendar era, from a year ending in a 1 to the next year ending in a 0.",

For example, the fourth dekad is Feb, 1 - Feb, 10 each year.

The Mmm, d notation combined with range (hyphen) makes this a bit hard to read.
Also I think it would be good to illustrate the variation of the last dekad of the months.

suggestion:

For example, the third dekad of a year spans from Jan/21 till Jan/31 (11 days), the fourth dekad spans from Feb/01 till Feb/10 (10 days) and the sixth dekad spans from Feb/21 till Feb/28 or Feb/29 in a leap year (8 or 9 days respectively).