feat(test): create simple docs for creating tests

app/tests/Creating Tests.md

@@ -0,0 +1,23 @@
+# Basics
+Any folder under `/app/tests` containing `native_posix.keymap` will be selected when running
+`./run-test.sh all`.
+
+`test_case/events.patterns` contains sed patterns that will select the interesting output from the
+application
+
+`test_case/keycode_events.snapshot` contains the expected output after applying `events.pattern` to
+the output
+
+`test_case/native_posix.keymap` defines the keys and the mock key presses. Most tests include a
+common keymap for their test set
+
+## Creating a New Test Set
+1. Copy the test set that most closely resembles the tests you will be creating.
+2. Rename the newly created test set to the behavior you're testing  e.g, toggle-layer
+3. Modify `behavior_keymap.dtsi` to create a keymap using the behavior and related behaviors
+4. Modify `test_case/native_posix.keymap` for a simulated use case
+5. Modify `test_case/events.patterns` to collect relevant logs to the test
+    - See: [sed manual](https://www.gnu.org/software/sed/manual/sed.html) and
+    [tutorial](https://www.digitalocean.com/community/tutorials/the-basics-of-using-the-sed-stream-editor-to-manipulate-text-in-linux)
+6. Modify `test_case/keycode_events.snapshot` for to include the expected output
+7. Repeat steps 4 to 6 for every test case