metrics: Add FIO general README

This PR adds FIO general README information.

Signed-off-by: Gabriela Cervantes <gabriela.cervantes.tellez@intel.com>

tests/metrics/storage/fio-k8s/README.md

@@ -0,0 +1,26 @@
+# FIO test in Kubernetes
+
+This is an automation to run `fio` with Kubernetes.
+
+## Requirements:
+- Kubernetes cluster running.
+- Kata configured as `runtimeclass`. 
+The test is structured as follow: 
+- [fio-test]: Program wrapper to launch `fio` in a K8s pod. 
+- [pkg]: Library code that could be used for more `fio` automation. 
+- [configs]: Configuration files used by [fio-test]. 
+- [DAX-compare-test]: Script to run [fio-test] to generate `fio` data for Kata with/without `virtio-fs DAX` and K8s bare-metal runtime(`runc`). 
+- [report] Jupyter Notebook to create reports for data generated by [DAX-compare-test].
+
+## Top-level Makefile targets
+- `build`: Build `fio` metrics.
+- `test`: quick test, used to verify changes in [fio-test]. 
+- `run`: Run `fio` metrics and generate reports. 
+- `test-report-interactive`: Run python notebook in `localhost:8888`, useful to edit the report. 
+- `test-report`: Generate report from data generated by `make test`. 
+
+[fio-test]:cmd/fiotest 
+[configs]:configs 
+[pkg]:pkg 
+[report]:scripts/dax-compare-test/report
+[DAX-compare-test]:scripts/dax-compare-test/README.md