boards: rename doc.txt -> doc.md for nrf boards

boards/nrf51dk/doc.md

@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_nrf51dk nRF51DK Development Kit
 @ingroup     boards
 @brief       Support for the Nordic nRF51DK Development Kit
@@ -31,4 +30,3 @@ To flash the board, use the following command:
 $ make BOARD=nrf51dk flash
 ```
 from any application directory.
- */

boards/nrf51dongle/doc.md

@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_nrf51dongle nRF51 Dongle
 @ingroup     boards
 @brief       Support for the Nordic nRF51 Dongle
@@ -51,4 +50,3 @@ To interact with the board just start the tool using the following command:
 For RIOT itself there is a Flash-Script available. When using any of the
 Examples type in the following command:
 `# Make -B clean flash`
- */

boards/nrf52832-mdk/doc.md

@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_nrf52832-mdk nRF52832-MDK
 @ingroup     boards
 @brief       Support for the nRF52832-MDK
@@ -44,4 +43,3 @@ Use the `term` target to connect to the board serial port<br/>
 ```
     make BOARD=nrf52832-mdk -C examples/basic/hello-world term
 ```
- */

boards/nrf52840-mdk-dongle/doc.md

@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_nrf52840-mdk-dongle nRF52840 MDK USB Dongle
 @ingroup     boards
 @brief       Support for the nRF52840 MDK USB Dongle
@@ -58,5 +57,3 @@ To ease debugging,
 pins 0.6 and 0.7 are configured as RX and TX, respectively.
 They provide stdio if no CDC-ACM is disabled,
 and can be used as a custom UART otherwise.
-
- */

boards/nrf52840-mdk/doc.md

@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_nrf52840-mdk nRF52840-MDK
 @ingroup     boards
 @brief       Support for the nRF52840-MDK
@@ -34,4 +33,3 @@ Use the `term` target to connect to the board serial port<br/>
 ```
     make BOARD=nrf52840-mdk -C examples/basic/hello-world term
 ```
- */

boards/nrf52dk/doc.md

@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_nrf52dk nRF52 DK
 @ingroup     boards
 @brief       Support for the nRF52 DK
@@ -64,4 +63,3 @@ Use the `term` target to connect to the board serial port<br/>
 ```
     make BOARD=nrf52dk -C examples/basic/hello-world term
 ```
- */

boards/nrf5340dk-app/doc.md

@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_nrf5340dk-app nRF5340DK
 @ingroup     boards
 @brief       Support for the nRF5340DK-app board
@@ -34,5 +33,3 @@ Use the `term` target to connect to the board serial port<br/>
 ```
     make BOARD=nrf5340dk-app -C examples/basic/hello-world term
 ```
-
- */

boards/nrf9160dk/doc.md

@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_nrf9160dk nRF9160DK
 @ingroup     boards
 @brief       Support for the nRF9160DK board
@@ -31,5 +30,3 @@ Use the `term` target to connect to the board serial port<br/>
 ```
     make BOARD=nrf9160dk -C examples/basic/hello-world term
 ```
-
- */

boards/waveshare-nrf52840-eval-kit/doc.md

@@ -1,4 +1,3 @@
-/**
 @defgroup   boards_waveshare_nrf52840_eval_kit Waveshare nRF52840 Eval Kit
 @ingroup    boards
 @brief      Support for the Waveshare nRF52840 Eval Kit
@@ -156,5 +155,3 @@ RESET_PIN='GPIO_PIN\(0,18\)' make BOARD=waveshare-nrf52840-eval-kit -C dist/tool
 ```
 Simply compile, flash, and run that tool on your board, and the reset pin should
 work for the time being.
-
- */

boards/yunjia-nrf51822/doc.md

@@ -1,4 +1,3 @@
-/**
 @defgroup    boards_yunjia-nrf51822 Yunjia NRF51822
 @ingroup     boards
 @brief       Support for the Yunjia NRF51822 board
@@ -239,4 +238,3 @@ configuration script with: `openocd -f boards/yunjia-nrf51822/dist/openocd.cfg`.
 `nrf51 mass_erase`.
 
 This should have erased the whole memory of the device.
- */