fix typos (#369)

Author: Zethson

src/rapids_singlecell/tools/_pymde.py

@@ -44,11 +44,11 @@ def mde(
 
     Notes
     -----
-        This function adapted from scvi-tools.
+        This function is adapted from scvi-tools.
         The appropriateness of use of visualization of high-dimensional spaces in single-
         cell omics remains an open research questions. See:
         Chari, Tara, Joeyta Banerjee, and Lior Pachter. "The specious art of single-cell genomics." bioRxiv (2021).
-        If you use this function in your research please cite:
+        If you use this function in your research, please cite:
         Agrawal, Akshay, Alnur Ali, and Stephen Boyd. "Minimum-distortion embedding." arXiv preprint arXiv:2103.02559 (2021).
     """
     try: