Added GLM to Math

Author: betajippity

README.md

@@ -358,6 +358,7 @@ A curated list of awesome C/C++ frameworks, libraries, resources, and shiny thin
 * [CGal](http://www.cgal.org/) - Collection of efficient and reliable geometric algorithms. [LGPL&GPL]
 * [cml](http://cmldev.net/) - free C++ math library for games and graphics. [Boost]
 * [Eigen](http://eigen.tuxfamily.org/) - A high-level C++ library of template headers for linear algebra, matrix and vector operations, numerical solvers and related algorithms. [MPL2]
+* [GLM](https://github.com/g-truc/glm) - Header-only C++ math library that matches and inter-operates with OpenGL's GLSL math. [MIT]
 * [GMTL](http://ggt.sourceforge.net/) - Graphics Math Template Library is a collection of tools implementing Graphics primitives in generalized ways. [GPL2]
 * [GMP](https://gmplib.org/) - A C/C++ library for arbitrary precision arithmetic, operating on signed integers, rational numbers, and floating-point numbers. [LGPL3 & GPL2]
 * [QuantLib](https://github.com/lballabio/quantlib) - A free/open-source library for quantitative finance. [Modified BSD] [website](http://quantlib.org/)