Add description to wma

Author: MDUYN

README.md

@@ -45,8 +45,11 @@ Indicators that help to determine the direction of the market (uptrend, downtren
 
 #### Weighted Moving Average (WMA)
 
+Moving average that gives more weight to recent data points by applying a weighting factor to the data points.
+
 ```python
 def wma(data: Union[PandasDataFrame, PolarsDataFrame], source_column: str, period: int, result_column: Optional[str] = None) -> Union[PdDataFrame, PlDataFrame]
+```
 
 ```python
 from investing_algorithm_framework import CSVOHLCVMarketDataSource