Add India Uppal to AUTHORS.md (#500)

Add India Uppal to the list of authors.

AUTHORS.md

@@ -12,4 +12,5 @@ order by last name) and are considered "The Harmonica Developers":
 * [Santiago Soler](https:/santisoler) - Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia (ORCID: 0000-0001-9202-5317)
 * [Matthew Tankersley](https:/mdtanker) - Antarctic Research Centre, Victoria University of Wellington, New Zealand (ORCID: 0000-0003-4266-8554)
 * [Leonardo Uieda](https:/leouieda) - Universidade de São Paulo, Brazil (ORCID: 0000-0001-6123-9515)
+* [India Uppal](https:/indiauppal) - The University of Liverpool, UK (ORCID: 0000-0003-3531-2656)
 * [ziebam](https:/ziebam) (not included in Zenodo)