[src][test] Fixing malloc corruption errors
[src] Simple matrix_append_row implementation
[src][test] Making append row functionality more robust
[src][test] Adding in an additional test to ensure data integrity after appending a row
[src][test] Similar implementation for appending a col, adding corresponding tests.  TODO Perhaps refactor some of the duplicate functionality
[src] Adding in a stdio.h include for matrix test to get rid of compiler warning
[src][docs] Updating docs to the suggested format