* MatrixMultiplication.java created and updated.
* Add necessary comment to MatrixMultiplication.java
* Create MatrixMultiplicationTest.java
* method for 2 by 2 matrix multiplication is created
* Use assertMatrixEquals(), otherwise there can be error due to floating point arithmetic errors
* assertMatrixEquals method created and updated
* method created for 3by2 matrix multiply with 2by1 matrix
* method created for null matrix multiplication
* method for test matrix dimension error
* method for test empty matrix input
* testMultiply3by2and2by1 test case updated
* Check for empty matrices part updated
* Updated Unit test coverage
* files updated
* clean the code
* clean the code
* Updated files with google-java-format
* Updated files
* Updated files
* Updated files
* Updated files
* Add reference links and complexities
* Add test cases for 1by1 matrix and non-rectangular matrix
* Add reference links and complexities
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Co-authored-by: Deniz Altunkapan <93663085+DenizAltunkapan@users.noreply.github.com>
