Add suport for Connaxio's Espoir

[ma-lalonde]

Adds the configuration file for Connaxio's Espoir devboard, a PoE+ mikroBUS^TM mainboard based on the ESP32.

More info: https://www.connaxio.com/electronics/espoir/

[valeros]

Thanks for the PR, will be merged once a new stable Arduino core with this board is available.

[ma-lalonde]

Hi @valeros, the arduino-esp32 master branch already has support for this board since #6822. Since Espoir uses a single-core CPU, Connaxio provides the compiled binaries on its own git via its release-single-core branch. All that is needed once this PR is merged is to add platform_packages = framework-arduinoespressif32 @ https://github.com/Connaxio/arduino-esp32.git#release-single-core to any project's platformio.ini to source the custom fork.

The gist of it all is that things will remain as they are for a while, so if it is acceptable to you that a custom Arduino fork is required, please let me know how/if it should be documented on platformio's side. I'll be grateful to have this board added to platformio's collection. Please let me know also if you'd still prefer to wait until Arduino v2.0.4 or if the current state of things is okay.

[valeros]

Many thanks for the PR, merged!