In some situations you would like to have a folder for libraries with some examples. There is a command in platform io to compile this structures of folders, like:

pio ci examples/sendTM.ino --board=nucleo_f446re --lib="." --build-dir /tmp/test --keep-build-dir

The structure of the folder looks something like:

- File.cpp
- File.h
- readme.md
- examples/
  - sendTM.ino

That you can use it to flash a microcontroller.