Updated OPTIMISATIONS.md

Author: nspyrop03

OPTIMISATIONS.md

@@ -122,3 +122,12 @@ if(TM->addPassesToEmitFile(PM, asmFile, nullptr, llvm::CGFT_AssemblyFile)) {
 }
 PM.run(*TheModule);
 ```
+
+## Runtime Comparison of Optimized Programs
+The following image generated with
+```bash
+python3 testing/test_compiler.py
+```
+illustrates the execution times of the programs under all optimisation levels implemented.
+
+![Time Comparison](testing/opt_times.png)