Added some missing Platform IO configuration details (#855)

* Added some missing Platform IO configuration details

* Add missing static target names

* @Acuadros95 added the missing boards defenitions

Author: amilcarlucas

README.md

@@ -78,6 +78,19 @@ build_flags =
     -D <TARGET_DEFINITION>
 ```
 
+| Board                       | <YOUR_BOARD>        | <BOARD_ARCHITECTURE>         | <TARGET_DEFINITION>                 |
+| ----------------------------| ------------------- | ---------------------------- | ----------------------------------- |
+| Arduino Portenta H7 M7 Core | portenta_h7_m7      | cortex-m7/fpv5-d16-softfp    | TARGET_PORTENTA_H7_M7               |
+| Arduino Nano RP2040 Connect | nanorp2040connect   | cortex-m0plus                | ARDUINO_NANO_RP2040_CONNECT         |
+| Teensy 4.1/4.0              | teensy41 / teensy40 | imxrt1062/fpv5-d16-hard      | ARDUINO_TEENSY41                    |
+| Teensy 3.6                  | teensy36            | mk66fx1m0/fpv4-sp-d16-hard   | ARDUINO_TEENSY36                    |
+| Teensy 3.5                  | teensy35            | mk64fx512/fpv4-sp-d16-hard   | ARDUINO_TEENSY35                    |
+| Teensy 3.2  / 3.1           | teensy31            | mk20dx256                    | ARDUINO_TEENSY32 / ARDUINO_TEENSY31 |
+| ESP32 Dev Module            | esp32dev            | esp32                        | ESP32                               |
+| STM32-E407                  | olimex_e407         | cortex-m4                    | TARGET_STM32F4                      |
+| Arduino Due                 | due                 | cortex-m3                    | -                                   |
+| Arduino Zero                | zero                | cortex-m0plus                | -                                   |
+
 Now to proceed with the PlatformIO workflow:
 
 ```bash
@@ -164,6 +177,15 @@ An example of a micro-ROS application using PlatformIO is available [here](https
 docker pull microros/micro_ros_static_library_builder:galactic
 docker run -it --rm -v $(pwd):/project --env MICROROS_LIBRARY_FOLDER=extras microros/micro_ros_static_library_builder:galactic
 ```
+
+Optionally a specific single target can be built using the `-p <LIBRARY_TARGET>` argument like this:
+
+```bash
+docker run -it --rm -v $(pwd):/project --env MICROROS_LIBRARY_FOLDER=extras microros/micro_ros_static_library_builder:galactic -p <LIBRARY_TARGET>
+```
+
+Available targets `LIBRARY_TARGETS` are available on the [top of the extras/library_generation/library_generation.sh file](https://github.com/micro-ROS/micro_ros_arduino/blob/main/extras/library_generation/library_generation.sh#L13-L24)
+
 Note that folders added to `extras/library_generation/extra_packages` and entries added to `extras/library_generation/extra_packages/extra_packages.repos` will be taken into account by this build system.
 
 ## Patch Arduino board for support precompiled libraries