XIAO RP2040, RP2040 SDK and APIs

Earle F. Philhower is always working :grin: … a new release of Arduino “core ” for RP2040 …

Release 2.5.0 - Full RP2040 Web Support - WebServer, HTTPUpdate Server added

Update version
Add ExtremeElectronics RC2040 (#799)
Add WebServer, WebServerSecure, HTTPUpdateServer, HTTPUpdateServerSecure (#791)
Fix functions in docs: RP2040 Helper Class (#793)

Guglielmo