added information about new line spacing modification shell scripts

Author: chrissimpkins

README.md

@@ -32,6 +32,8 @@ You can now modify the default line spacing in Hack fonts with our new `font-lin
 
 https://github.com/source-foundry/font-line
 
+or [use one of our handy shell scripts](https://github.com/chrissimpkins/Hack/tree/master/tools/line-spacing) that automates the `font-line` install and line spacing modification process for a range of line spacing % UPM values between 10 - 30%.  Select the script that fits your needs and execute it in the directory that contains your .ttf and/or .otf font files.
+
 
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