add setup instructions

Author: mc-cat-tty

README.md

@@ -1,5 +1,9 @@
 # Development Environment for Tricore GCC + ERIKA Enterprise
 
+# Setup
+```bash
+git clone --recurse-submodules --shallow-submodules https://github.com/mc-cat-tty/tricore-dev-env
+```
 
 ## Examples
 Please, note that the linker script _.lsl_ file is not the default one provided by [Infineon Code Examples](https://github.com/Infineon/AURIX_code_examples). It has been downloaded from this [URL](https://nextcloud.hightec-rt.com/index.php/s/BG72PCMP7jrEcki), as suggested by [AURIX Development Studio - Guide for HighTec Toolchains](https://free-entry-toolchain.hightec-rt.com/aurix_dev_studio_with_hightec_gcc.pdf).