Update tutorial.md

* Remove section on licensing

Author: longradix

tutorial.md

@@ -174,14 +174,3 @@ User interactions are not part of `gnuplot_i`. It is however possible to resize
 No timing mechanisms are provided to leave the outputs on screen until for example a key is pressed. However, an example of how user interaction could be provided is included in the function `gnuplot_plot_once()`.
 
 This library was developed since early versions of `gnuplot` and not all new functionality added since is supported by this library, such as some plotting styles.
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-Licensing
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-This library has been licensed under the GPL, same as all other GNU software, and is therefore less strict than the [gnuplot license](https://spdx.org/licenses/gnuplot.html) itself. 
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-* Nicolas Devillard - April 2000
-* Robert Bradley - 2006
-* longradix - July 2023