Update README notation rendering

README.md

@@ -45,7 +45,7 @@ To detect regions with significantly elevated mutation density, a Poisson right-
 
 $$p = P(X \geq k \mid \lambda)$$
 
-where $k$ is the observed mutation count in a window and $\lambda$ is the background mutation rate, estimated as the mean mutation count of all windows within the same chromosome. P-values were corrected for multiple testing using the Benjamini–Hochberg FDR procedure, and windows with FDR < 0.05 were labeled as mutation hotspots (label = 1).
+where **k** is the observed mutation count in a window and **λ** is the background mutation rate, estimated as the mean mutation count of all windows within the same chromosome. P-values were corrected for multiple testing using the Benjamini–Hochberg FDR procedure, and windows with FDR < 0.05 were labeled as mutation hotspots (label = 1).
 
 ### 4. Non-hotspot sampling and balancing  
 To construct a balanced dataset, an equal number of non-hotspot windows (label = 0) were randomly sampled from the remaining genomic regions of the same chromosome.