Add mbed_nano to list of compatible architectures

In the recent 2.0.0 release of the Arduino Mbed OS Boards platform, the mbed architecture split into four architectures:

- mbed_edge: Arduino Edge Control
- mbed_nano: Nano 33 BLE and Nano RP2040 Connect
- mbed_rp2040: Raspberry Pi Pico
- mbed_portenta: Portenta H7

The mbed architecture should be retained for backwards support, but the new mbed_nano should also be added to avoid spurious incompatibility warnings and the library's examples being shown under the File > Examples > INCOMPATIBLE menu of the Arduino IDE when the Nano 33 BLE board is selected.

Author: per1234

library.properties

@@ -6,7 +6,7 @@ sentence=This library enables you to use Interrupt from Hardware Timers on an NR
 paragraph=These nRF52 Hardware Timers, using Interrupt, still work even if other functions are blocking. Moreover, they are much more precise (certainly depending on clock frequency accuracy) than other software timers using millis() or micros(). That's mandatory if you need to measure some data requiring better accuracy. It now supports 16 ISR-based Timers, while consuming only 1 Hardware Timer. Timers' interval is very long (ulong millisecs). The most important feature is they're ISR-based Timers. Therefore, their executions are not blocked by bad-behaving functions or tasks. This important feature is absolutely necessary for mission-critical tasks.
 category=Timing,Control,Device,Time,Timer,NRF52,interrupt,mbed
 url=https://github.com/khoih-prog/NRF52_MBED_TimerInterrupt
-architectures=mbed,nrf52
+architectures=mbed,mbed_nano,nrf52
 repository=https://github.com/khoih-prog/NRF52_MBED_TimerInterrupt
 license=MIT
 includes=NRF52_MBED_TimerInterrupt.h,NRF52_MBED_ISR_Timer.h