Add support for new NRF52 board, MeshLink (#5736)

* Add support for MeshLink

* Updated, enabled watchdog and added button definition

* added eink variant and removed some compile errors

* Small board json file edit

* Finally got trunk working (somehow?), this is just cleanup with trunk fmt

* Various improvements and cleanup. Removed the use of PIN_3V3_En and defined a specific WD_EN pin instead for better clarity. Will do a bit more testing asap to make sure everything still works as intended :)

* Enable on-board QSPI Flash

* run trunk fmt with clang-format

---------

Co-authored-by: Ben Meadors <benmmeadors@gmail.com>
Co-authored-by: Thomas Göttgens <tgoettgens@gmail.com>
Co-authored-by: Austin <vidplace7@gmail.com>

src/sleep.cpp

@@ -245,6 +245,9 @@ void doDeepSleep(uint32_t msecToWake, bool skipPreflight = false, bool skipSaveN
 #ifdef PIN_3V3_EN
     digitalWrite(PIN_3V3_EN, LOW);
 #endif
+#ifdef PIN_WD_EN
+    digitalWrite(PIN_WD_EN, LOW);
+#endif
 #endif
     ledBlink.set(false);
 
@@ -530,4 +533,4 @@ void enableLoraInterrupt()
     }
 #endif
 }
-#endif
+#endif