drone: Update README

drone/README.md

@@ -1,7 +1,43 @@
 # Client of clever-show
 
-Application for remote synchronized control of drones and emergency drone protection module.
+Application for remote synchronized control of drones and failsafe drone protection module.
+
+* `client.py` is the main drone communication and control module
+* `failsafe.py` is the drone protection module, which creates `/emergency_land` service and monitors the state of the drone in accordance with the logic specified in `[FAILSAFE]` item of `client.ini` settings file
+
+## Requirements
+
+* Ubuntu Bionic or Debian Stretch
+* ROS Melodic
+* Clover ROS package
+* Python 2.7
+* Time synchronization client
+
+Can be used with built-in NTP client or with external package for time synchronization like `chrony` on Linux systems.
+
+## Installation
+
+```cmd
+pip install -r requirements.txt
+```
+
+## Usage
+
+Start roscore with clover package on the drone or on the PC with drone simulator.
+
+Start client:
+
+```cmd
+python client.py
+```
+
+If you want to start failsafe module, execute in the other terminal:
+
+```cmd
+python failsafe.py
+```
+
+## Documentation
 
-Documentation is located here:
 * English
 * [Russian](../docs/ru/client.md)