Add google scholar social icon (#22)

moderncviconsmarvosym.sty

@@ -225,6 +225,7 @@
   ~}
 \renewcommand*{\gitlabsocialsymbol}{}
 \renewcommand*{\stackoverflowsocialsymbol}{}
+\renewcommand*{\googlescholarsocialsymbol}{}
 \renewcommand*{\telegramsocialsymbol}{}
 \renewcommand*{\orcidsocialsymbol}{}
 \renewcommand*{\researchgatesocialsymbol}{}