replace arrow url with github

README.md

@@ -82,7 +82,7 @@ A collection of resources for working with sequential and time series data
 *Libraries for working with dates and times.*
 
 - [astral](https://github.com/sffjunkie/astral) Python calculations for the position of the sun and moon.
-- [Arrow](https://arrow.readthedocs.io/en/latest/) - A Python library that offers a sensible and human-friendly approach to creating, manipulating, formatting and converting dates, times and timestamps.
+- [Arrow](https://github.com/arrow-py/arrow) - A Python library that offers a sensible and human-friendly approach to creating, manipulating, formatting and converting dates, times and timestamps.
 - [Chronyk](https://github.com/KoffeinFlummi/Chronyk) - A Python 3 library for parsing human-written times and dates.
 - [dateutil](https://github.com/dateutil/dateutil) - Extensions to the standard Python [datetime](https://docs.python.org/3/library/datetime.html) module.
 - [delorean](https://github.com/myusuf3/delorean/) - A library for clearing up the inconvenient truths that arise dealing with datetimes.