added Abstract in README

README.md

@@ -1,2 +1,17 @@
 # The-Art-of-Linear-Algebra
 Graphic notes on Gilbert Strang's "Linear Algebra for Everyone"
+
+The output file is "The-Art-of-Linear-Algebra.pdf"
+
+## Abstract
+I tried intuitive visualizations of important concepts introduced
+in ``Linear Algebra for Everyone".
+This is aimed at promoting understanding of vector/matrix calculations
+and algorithms from the\linebreak perspectives of matrix factorizations.
+They include Column-Row ($\bm{CR}$), Gaussian Elimination ($\bm{LU}$),
+Gram-Schmidt Orthogonalization ($\bm{QR}$), Eigenvalues and Diagonalization ($\bm{Q \Lambda Q^\mathbf{T}}$),
+and Singular Value Decomposition ($\bm{U \Sigma V^\mathbf{T}}$).
+
+![](5-Factorizations.png)
+
+