Update install script

install

@@ -238,8 +238,9 @@ for shell in bash zsh; do
 
   echo "Update $rc:"
   echo "  - $src"
-  if [ $(grep -F "$src" $rc | wc -l) -gt 0 ]; then
-    echo "    - Not added (already being sourced)"
+  line=$(grep -nF "$src" $rc | sed 's/:.*//')
+  if [ -n "$line" ]; then
+    echo "    - Already exists (line #$line)"
   else
     echo $src >> $rc
     echo "    - Added"
@@ -253,5 +254,7 @@ Finished. Reload your .bashrc or .zshrc.
    source ~/.zshrc   # zsh
 
 To uninstall fzf, simply remove the added line.
+
+For more information, see: https://github.com/junegunn/fzf
 EOF