feat(esphome): Add initial irrigation system configuration

This commit introduces the initial ESPHome configuration for the irrigation system.

- `irrigation_system.yaml`: ESPHome configuration with Modbus valve control.

- `create_secrets.py`: Script to generate `secrets.yaml`.

- `secrets.yaml.example`: Example secrets file.

- `requirements.txt`: Python dependencies.

- `.gitignore`: Standard ESPHome gitignore file.
Signed-off-by: Eduard Iten <eduard@iten.pro>

software/esphome/.gitignore

@@ -0,0 +1,5 @@
+# Gitignore settings for ESPHome
+# This is an example and may include too much for your use-case.
+# You can modify this file to suit your needs.
+/.esphome/
+/secrets.yaml