Update README.md

- Add badges for stable fw images

Author: josesimoes

README.md

@@ -56,14 +56,14 @@ The **preview** versions are continuous builds of the reference targets. They in
 
 | Target | Stable | Preview |
 |:-|---|---|
-| ST_STM32F4_DISCOVERY | []() |  [![Download](https://api.bintray.com/packages/nfbot/nanoframework-images-dev/ST_STM32F4_DISCOVERY/images/download.svg)](https://bintray.com/nfbot/nanoframework-images-dev/ST_STM32F4_DISCOVERY/_latestVersion) |
-| ST_STM32F429I_DISCOVERY | []() | [ ![Download](https://api.bintray.com/packages/nfbot/nanoframework-images-dev/ST_STM32F429I_DISCOVERY/images/download.svg) ](https://bintray.com/nfbot/nanoframework-images-dev/ST_STM32F429I_DISCOVERY/_latestVersion) |
-| ST_NUCLEO64_F091RC | []() | [ ![Download](https://api.bintray.com/packages/nfbot/nanoframework-images-dev/ST_NUCLEO64_F091RC/images/download.svg) ](https://bintray.com/nfbot/nanoframework-images-dev/ST_NUCLEO64_F091RC/_latestVersion) |
-| ST_NUCLEO144_F746ZG | []() | [ ![Download](https://api.bintray.com/packages/nfbot/nanoframework-images-dev/ST_NUCLEO144_F746ZG/images/download.svg) ](https://bintray.com/nfbot/nanoframework-images-dev/ST_NUCLEO144_F746ZG/_latestVersion) |
-| ST_STM32F769I_DISCOVERY | []() | [ ![Download](https://api.bintray.com/packages/nfbot/nanoframework-images-dev/ST_STM32F769I_DISCOVERY/images/download.svg) ](https://bintray.com/nfbot/nanoframework-images-dev/ST_STM32F769I_DISCOVERY/_latestVersion) |
-| MBN_QUAIL | []() | [ ![Download](https://api.bintray.com/packages/nfbot/nanoframework-images-dev/MBN_QUAIL/images/download.svg) ](https://bintray.com/nfbot/nanoframework-images-dev/MBN_QUAIL/_latestVersion) |
-| NETDUINO3_WIFI | []() | [ ![Download](https://api.bintray.com/packages/nfbot/nanoframework-images-dev/NETDUINO3_WIFI/images/download.svg) ](https://bintray.com/nfbot/nanoframework-images-dev/NETDUINO3_WIFI/_latestVersion) |
-| ESP32_DEVKITC | []() | [ ![Download](https://api.bintray.com/packages/nfbot/nanoframework-images-dev/ESP32_DEVKITC/images/download.svg) ](https://bintray.com/nfbot/nanoframework-images-dev/ESP32_DEVKITC/_latestVersion) |
+| ST_STM32F4_DISCOVERY | [![Download](https://api.bintray.com/packages/nfbot/nanoframework-images/ST_STM32F4_DISCOVERY/images/download.svg)](https://bintray.com/nfbot/nanoframework-images/ST_STM32F4_DISCOVERY/_latestVersion) |  [![Download](https://api.bintray.com/packages/nfbot/nanoframework-images-dev/ST_STM32F4_DISCOVERY/images/download.svg)](https://bintray.com/nfbot/nanoframework-images-dev/ST_STM32F4_DISCOVERY/_latestVersion) |
+| ST_STM32F429I_DISCOVERY | [ ![Download](https://api.bintray.com/packages/nfbot/nanoframework-images/ST_STM32F429I_DISCOVERY/images/download.svg) ](https://bintray.com/nfbot/nanoframework-images/ST_STM32F429I_DISCOVERY/_latestVersion) | [ ![Download](https://api.bintray.com/packages/nfbot/nanoframework-images-dev/ST_STM32F429I_DISCOVERY/images/download.svg) ](https://bintray.com/nfbot/nanoframework-images-dev/ST_STM32F429I_DISCOVERY/_latestVersion) |
+| ST_NUCLEO64_F091RC | [ ![Download](https://api.bintray.com/packages/nfbot/nanoframework-images/ST_NUCLEO64_F091RC/images/download.svg) ](https://bintray.com/nfbot/nanoframework-images/ST_NUCLEO64_F091RC/_latestVersion) | [ ![Download](https://api.bintray.com/packages/nfbot/nanoframework-images-dev/ST_NUCLEO64_F091RC/images/download.svg) ](https://bintray.com/nfbot/nanoframework-images-dev/ST_NUCLEO64_F091RC/_latestVersion) |
+| ST_NUCLEO144_F746ZG | [ ![Download](https://api.bintray.com/packages/nfbot/nanoframework-images/ST_NUCLEO144_F746ZG/images/download.svg) ](https://bintray.com/nfbot/nanoframework-images/ST_NUCLEO144_F746ZG/_latestVersion) | [ ![Download](https://api.bintray.com/packages/nfbot/nanoframework-images-dev/ST_NUCLEO144_F746ZG/images/download.svg) ](https://bintray.com/nfbot/nanoframework-images-dev/ST_NUCLEO144_F746ZG/_latestVersion) |
+| ST_STM32F769I_DISCOVERY | [ ![Download](https://api.bintray.com/packages/nfbot/nanoframework-images/ST_STM32F769I_DISCOVERY/images/download.svg) ](https://bintray.com/nfbot/nanoframework-images/ST_STM32F769I_DISCOVERY/_latestVersion) | [ ![Download](https://api.bintray.com/packages/nfbot/nanoframework-images-dev/ST_STM32F769I_DISCOVERY/images/download.svg) ](https://bintray.com/nfbot/nanoframework-images-dev/ST_STM32F769I_DISCOVERY/_latestVersion) |
+| MBN_QUAIL | [ ![Download](https://api.bintray.com/packages/nfbot/nanoframework-images/MBN_QUAIL/images/download.svg) ](https://bintray.com/nfbot/nanoframework-images/MBN_QUAIL/_latestVersion) | [ ![Download](https://api.bintray.com/packages/nfbot/nanoframework-images-dev/MBN_QUAIL/images/download.svg) ](https://bintray.com/nfbot/nanoframework-images-dev/MBN_QUAIL/_latestVersion) |
+| NETDUINO3_WIFI | [ ![Download](https://api.bintray.com/packages/nfbot/nanoframework-images/NETDUINO3_WIFI/images/download.svg) ](https://bintray.com/nfbot/nanoframework-images/NETDUINO3_WIFI/_latestVersion) | [ ![Download](https://api.bintray.com/packages/nfbot/nanoframework-images-dev/NETDUINO3_WIFI/images/download.svg) ](https://bintray.com/nfbot/nanoframework-images-dev/NETDUINO3_WIFI/_latestVersion) |
+| ESP32_DEVKITC | [ ![Download](https://api.bintray.com/packages/nfbot/nanoframework-images/ESP32_DEVKITC/images/download.svg) ](https://bintray.com/nfbot/nanoframework-images/ESP32_DEVKITC/_latestVersion) | [ ![Download](https://api.bintray.com/packages/nfbot/nanoframework-images-dev/ESP32_DEVKITC/images/download.svg) ](https://bintray.com/nfbot/nanoframework-images-dev/ESP32_DEVKITC/_latestVersion) |
 
 
 The above firmware builds include support for the class libraries and features marked bellow.