Add BF lua logo to readme

Author: klutvott123

README.md

@@ -1,4 +1,5 @@
-# Betaflight TX Lua Scripts
+![BF lua logo light mode](docs/assets/images/bf_lua_logo_light_mode.png#gh-light-mode-only)
+![BF lua logo dark mode](docs/assets/images/bf_lua_logo_dark_mode.png#gh-dark-mode-only)
 
  [![Latest version](https://img.shields.io/github/v/release/betaflight/betaflight-tx-lua-scripts)](https://github.com/betaflight/betaflight-tx-lua-scripts/releases) [![Build Status](https://api.travis-ci.com/betaflight/betaflight-tx-lua-scripts.svg?branch=master)](https://travis-ci.com/betaflight/betaflight-tx-lua-scripts) [![Build Status](https://dev.azure.com/Betaflight/Betaflight%20Nightlies/_apis/build/status/betaflight.betaflight-tx-lua-scripts?branchName=master)](https://dev.azure.com/Betaflight/Betaflight%20Nightlies/_build/latest?definitionId=1&branchName=master) [![License: GPL v3](https://img.shields.io/badge/License-GPLv3-blue.svg)](https://www.gnu.org/licenses/gpl-3.0)