doc: fix github urls to use the new org

Signed-off-by: Fabio Utzig <fabio.utzig@nordicsemi.no>
diff --git a/docs/readme-mbed.md b/docs/readme-mbed.md
index e94b4cb..189c7bf 100644
--- a/docs/readme-mbed.md
+++ b/docs/readme-mbed.md
@@ -16,7 +16,7 @@
 * `"mcuboot.max-img-sectors"`: maximum number of sectors, should be at least the number of sectors in each slot
 * `"target.restrict_size"`: the maximum size of the bootloader, such that it does not overlap with the primary slot
 
-More configurations such as signing algorithm, slot swapping, etc. can be found in [mbed_lib.json](https://github.com/JuulLabs-OSS/mcuboot/tree/master/boot/mbed/mbed_lib.json). Please note that certain features are not currently supported.
+More configurations such as signing algorithm, slot swapping, etc. can be found in [mbed_lib.json](https://github.com/mcu-tools/mcuboot/tree/master/boot/mbed/mbed_lib.json). Please note that certain features are not currently supported.
 
 ### Providing a secondary slot