[ENHANCEMENT] add README to test directory

Fixes intel#234

Signed-off-by: Kinga Stefaniuk <kinga.stefaniuk@intel.com>

tests/README.md

@@ -0,0 +1,30 @@
+## Running tests with pytest
+
+To run tests suite, make sure python and pytest with at least 3.11 version is installed.
+
+## How to compile with tests enabled
+
+Run `autogen.sh` to generate compilation configurations.
+Run `./configure` with `--enable-test` to enable building unit tests and add a target for `make check`. This option requires `--enable-library` too.
+Compile with `make` or `make check` when you want to run unit tests just after compilation.
+
+## Parameters to configure
+
+There is possibility to set:
+
+- `--ledctl-binary` - path to ledctl,
+- `--slot-filters` - comma separated list of slot filters to exclude,
+- `--controller-filters` - comma separated list of controller types to exclude.
+
+
+## How to run tests
+
+There are few methods to run tests:
+
+- run `pytest` with or without parameters to set,
+
+```shell
+$ pytest --ledctl-binary=src/ledctl/ledctl --slot-filters=sg3-,sg2- --controller-filters=VMD
+```
+- run `make check` which will compile the code and run tests. Logs will be placed in `./test-suite.log` file,
+- run script `tests/runtests.sh`.