Update README with citation details

Added citation information for CiteSource.

Author: TNRiley

README.md

@@ -21,6 +21,7 @@ Development of this project began as part of the Evidence Synthesis Hackathon an
 CiteSource was created under [the General Public License (>=v3)](https://www.gnu.org/licenses/gpl-3.0.html). 
 
 **Citing CiteSource**
+
 Riley, T. N., Young, S., Paxton, A. B., Wallrich, L., Hair, K., & Grainger, M. J. (2026). CiteSource: An R Package for Data-Driven Search Strategy Development and Enhanced Evidence Synthesis Reporting. Research Synthesis Methods. (DOI/PUBLICATION FORTHCOMING)
 
 **Shiny Web Application**