Merge pull request #359 from aidancuckoo/patch-1

Update pca10059.md

Author: tannewt

_board/pca10059.md

@@ -13,7 +13,15 @@ features:
 The nRF52840 dongle from Nordic Semiconductor is a small, low-cost USB dongle for Bluetooth Low Energy, Bluetooth mesh, Thread, ZigBee, 802.15.4, ANT, and 2.4 GHz proprietary applications using the nRF52840 SoC. The dongle has been designed to be used as a wireless HW device together with nRF Connect for Desktop.
 
 ## Purchase
-* [Comparison](https://www.nordicsemi.com/About-us/BuyOnline?search_token=nRF52840DONGLE)
+* [Price Comparison](https://www.nordicsemi.com/About-us/BuyOnline?search_token=nRF52840DONGLE)
+* [Symmetry Electronics](https://www.semiconductorstore.com/cart/pc/viewPrd.asp?idproduct=94964&utm_source=OemSecrets&utm_medium=compref&utm_campaign=OemSecrets&utm_term=NRF52840-DONGLE)
+* [Digi-Key](https://www.digikey.com/product-detail/en/nordic-semiconductor-asa/NRF52840-DONGLE/1490-1073-ND/9491124?utm_source=oemsecrets&utm_medium=aggregator&utm_campaign=buynow)
+* [Arrow Electronics](https://www.arrow.com/en/products/nrf52840-dongle/nordic-semiconductor?utm_source=oemsecrets&utm_medium=aggregator&utm_campaign=oemsecrets_2019_arrow&utm_content=inv_listing&utm_keyword=NRF52840-DONGLE)
+* [Avnet America](https://www.avnet.com/shop/us/products/nordic-semiconductor/nrf52840-dongle-3074457345635709668?CMP=EMA_OEMSecrets_inventoryfeed_VSE)
+* [Mouser](https://www.mouser.co.uk/ProductDetail/Nordic-Semiconductor/nRF52840-Dongle?qs=gTYE2QTfZfTbdrOaMHWEZg==&utm_source=OEMSECRETS&utm_medium=aggregator&utm_campaign=nRF52840-Dongle&utm_term=nRF52840DONGLE&utm_content=Nordic+Semiconductor)
+* [element14 Farnell](https://sg.element14.com/nordic-semiconductor/nrf52840-dongle/bluetooth-module-v5-2mbps/dp/2902521?CMP=GRHB-OEMSECRETS)
+* [Avnet Europe/Middle East/Africa](https://www.avnet.com/shop/emea/products/nordic-semiconductor/nrf52840-dongle-3074457345635584192?c=EUR&r=EMEA&CMP=EMEA_OEMSecrets_inventoryfeed_VSE)
+* [TME](https://www.tme.eu/en/details/nrf52840-dongle/development-kits-for-data-transmission/nordic-semiconductor/?utm_source=oemsecrets.com&utm_medium=cpc&utm_campaign=compare-2020-01)
 
 ## Contribute