Fix links to holidays package (#2999)

* Fix links to holidays package

Co-authored-by: Zhihao Dai <zhihao.dai@eng.ox.ac.uk>

* Update links to package documentation

Co-authored-by: Zhihao Dai <zhihao.dai@eng.ox.ac.uk>

* Update CHANGELOG

Co-authored-by: Zhihao Dai <zhihao.dai@eng.ox.ac.uk>

* Fix CHANGELOG typo

Co-authored-by: Zhihao Dai <zhihao.dai@eng.ox.ac.uk>

Author: daidahao

CHANGELOG.md

@@ -26,6 +26,7 @@ but cannot always guarantee backwards compatibility. Changes that may **break co
 - Fixed bug in `StaticCovariatesTransformer` where one-hot encoded column names were incorrectly assigned when the order of columns specified in `cols_cat` differed from the actual data column order. This caused silent data corruption where column names combined wrong feature names with wrong category values (e.g., `City_US` instead of `Country_US`). [#2989](https://github.com/unit8co/darts/pull/2989) by [Dustin Brunner](https://github.com/brunnedu).
 - Fixed a bug in `TorchTrainingDataset` where `max_samples_per_ts` was not acting as an upper bound on the number of samples per time series. Now `max_samples_per_ts` correctly acts as an upper bound, capping the dataset size at the actual number of samples that can be extracted from the longest series. [#2987](https://github.com/unit8co/darts/pull/2987) by [Dustin Brunner](https://github.com/brunnedu).
 - Updated s(m)ape to not raise a ValueError when actuals and predictions are zero for the same timestep. [#2984](https://github.com/unit8co/darts/pull/2984) by [eschibli](https://github.com/eschibli).
+- Updated outdated links to [holidays package](https://holidays.readthedocs.io/en/latest/#available-countries) in `TimeSeries`, `holidays_timeseries()`, and `Prophet`. [#2999](https://github.com/unit8co/darts/pull/2999) by [Zhihao Dai](https://github.com/daidahao).
 
 **Dependencies**
 

darts/models/forecasting/prophet_model.py

@@ -97,13 +97,9 @@ def __init__(
             ..
         country_holidays
             An optional country code, for which holidays can be taken into account by Prophet.
+            See `holidays package <https://holidays.readthedocs.io/en/latest/#available-countries>`__ for available
+            country codes.
 
-            See: https://github.com/dr-prodigy/python-holidays
-
-            In addition to those countries, Prophet includes holidays for these
-            countries: Brazil (BR), Indonesia (ID), India (IN), Malaysia (MY), Vietnam (VN),
-            Thailand (TH), Philippines (PH), Turkey (TU), Pakistan (PK), Bangladesh (BD),
-            Egypt (EG), China (CN), and Russia (RU).
         cap
             Parameter specifying the maximum carrying capacity when predicting with logistic growth.
             Mandatory when `growth = 'logistic'`, otherwise ignored.

darts/timeseries.py

@@ -3532,7 +3532,7 @@ def add_holidays(
 
         The holiday component is binary where `1` corresponds to a time step falling on a holiday.
 
-        Available countries can be found `here <https://github.com/dr-prodigy/python-holidays#available-countries>`__.
+        Available countries can be found `here <https://holidays.readthedocs.io/en/latest/#available-countries>`__.
 
         This works only for deterministic time series (i.e., made of 1 sample).
 

darts/utils/timeseries_generation.py

@@ -520,7 +520,7 @@ def holidays_timeseries(
     Creates a binary univariate TimeSeries with index `time_index` that equals 1 at every index that lies within
     (or equals) a selected country's holiday, and 0 otherwise.
 
-    Available countries can be found `here <https://github.com/dr-prodigy/python-holidays#available-countries>`__.
+    Available countries can be found `here <https://holidays.readthedocs.io/en/latest/#available-countries>`__.
 
     Parameters
     ----------