feat(metadata): Add MakerDiary nRF52840 M.2 interconnect

* Add interconnect details.
* Add m60 and nrf52840_m2 metadata files.

app/boards/arm/nrf52840_m2/nrf52840_m2.zmk.yml

@@ -0,0 +1,10 @@
+file_format: "1"
+id: nrf52840_m2
+name: nRF52840 M.2 Module
+type: board
+arch: arm
+outputs:
+  - usb
+  - ble
+url: https://wiki.makerdiary.com/nrf52840-m2/
+exposes: [makerdiary_nrf52840_m2]

app/boards/interconnects/makerdiary_nrf52840_m2/makerdiary_nrf52840_m2.zmk.yml

@@ -0,0 +1,10 @@
+file_format: "1"
+id: makerdiary_nrf52840_m2
+name: MakerDiary nRF52840 M.2
+type: interconnect
+url: https://wiki.makerdiary.com/nrf52840-m2/
+manufacturer: MakerDiary
+description: |
+  The MakerDiary nRF52840 M.2 module is a module using the M.2/NGFF form factor to expose a
+  large number of GPIO pins, allowing use of a variety of peripherals such using I2C, SPI,
+  etc.

app/boards/shields/m60/m60.zmk.yml

@@ -0,0 +1,8 @@
+file_format: "1"
+id: m60
+name: MakerDiary m60
+type: shield
+url: https://makerdiary.com/pages/m60-mechanical-keyboard
+requires: [makerdiary_nrf52840_m2]
+features:
+  - keys