Readme: fix missing "

Change-Id: I51c767244b149aeceb3d53603f11753d772d8126
diff --git a/Readme.md b/Readme.md
index f6fd47b..76a26f5 100644
--- a/Readme.md
+++ b/Readme.md
@@ -31,7 +31,7 @@
 ### Requirements
 
 ```bash
-R -e "install.packages(c('devtools', 'RKorAPClient', 'httr', 'shiny', 'shinythemes', 'highcharter'))
+R -e "install.packages(c('devtools', 'RKorAPClient', 'httr', 'shiny', 'shinythemes', 'highcharter'))"
 R -e 'devtools::install_git("https://korap.ids-mannheim.de/gerrit/IDS-Mannheim/idsThemeR")'
 ```