Update product spec links and add DK guide links

Author: lachlan-smith

README.md

@@ -25,10 +25,14 @@ Every nRF chip has its own crate, listed below:
 
 ## Device Reference Manuals from Nordic
 
-- [nRF52840 Reference Manual](http://infocenter.nordicsemi.com/pdf/nRF52840_PS_v1.0.pdf)
-- [nRF52832 Reference Manual](http://infocenter.nordicsemi.com/pdf/nRF52832_PS_v1.4.pdf)
-- [nRF52810 Reference Manual](http://infocenter.nordicsemi.com/pdf/nRF52810_PS_v1.2.pdf)
-- [nRF9160 Reference Manual](http://infocenter.nordicsemi.com/pdf/nRF9160_PS_v1.1.pdf)
+| Device | Product Specification | DK Reference Guide |
+|-------|------|-----------|
+| [`nRF52810`](https://www.nordicsemi.com/Products/Low-power-short-range-wireless/nRF52810) | [`v1.3`](https://infocenter.nordicsemi.com/pdf/nRF52810_PS_v1.3.pdf) | [`v1.3.1*`](https://infocenter.nordicsemi.com/pdf/nRF52_DK_User_Guide_v1.3.1.pdf) |
+| [`nRF52832`](https://www.nordicsemi.com/Products/Low-power-short-range-wireless/nRF52832) | [`v1.4`](https://infocenter.nordicsemi.com/pdf/nRF52832_PS_v1.4.pdf) | [`v1.3.1*`](https://infocenter.nordicsemi.com/pdf/nRF52_DK_User_Guide_v1.3.1.pdf) |
+| [`nRF52833`](https://www.nordicsemi.com/Products/Low-power-short-range-wireless/nRF52833) | [`v1.3`](https://infocenter.nordicsemi.com/pdf/nRF52833_PS_v1.3.pdf) | [`v1.0.1`](http://infocenter.nordicsemi.com/pdf/nRF52833_DK_User_Guide_v1.0.1.pdf) |
+| [`nRF52840`](https://www.nordicsemi.com/Products/Low-power-short-range-wireless/nRF52840) | [`v1.1`](https://infocenter.nordicsemi.com/pdf/nRF52840_PS_v1.1.pdf) | [`v1.2`](https://infocenter.nordicsemi.com/pdf/nRF52840_DK_User_Guide_v1.2.pdf) |
+| [`nRF9160`](https://www.nordicsemi.com/Products/Low-power-cellular-IoT/nRF9160) | [`v2.0`](https://infocenter.nordicsemi.com/pdf/nRF9160_PS_v2.0.pdf) | [`v0.9.3`](https://infocenter.nordicsemi.com/pdf/nRF9160_DK_HW_User_Guide_v0.9.3.pdf) |
+\* These devices do not have a seperate developement kit and share the [NRF52 DK](https://www.nordicsemi.com/Software-and-tools/Development-Kits/nRF52-DK)
 
 ## License