Update README.md

README.md

@@ -37,7 +37,7 @@ pip install riassigner
 ```
 
 ## Usage
-RIAssigner can be used to read data from `.msp`, `.csv` and `.tsv` files using [matchms](https://github.com/matchms/matchms) and [pandas](https://pandas.pydata.org/) and to compute the retention indices for the data.
+RIAssigner can be used to read data from `.msp` and `.mgf` files using [matchms](https://github.com/matchms/matchms) and `.csv`, `.tsv` and `.parquet` using [pandas](https://pandas.pydata.org/) and to compute the retention indices for the data.
 A reference list of retention indexed compounds (traditionally an Alkane series) with retention times is used to compute the RI for a query dataset of retention time values using the [van Den Dool and Kratz](https://doi.org/10.1016/S0021-9673(01)80947-X) method or by using [cubic spline-based interpolation](https://doi.org/10.1021/ac50035a026).
 ### Example
 ```python