Infineon: Add cyw20829 platform, shared slot feature, json memory map, psoc6 xip

Based in 1.8.0 release of MCUBoot library

This commit adds CYW20829 Infineon platform support with following capabilities:
1. Overwrite and swap upgrade mode support
2. Multi-image with up to 4 images
3. Hardware security counter is supported for CYW20829 platform

Add XIP support for PSOC6 platform - place BOOT slot in external memory and execute it in place using SMIF in XIP mode

and some new features for Infineon devices.

1. Shared upgrade slot feature - use one shared area for upgrade slots of multiple images
2. Memory map defined using JSON file - define memory regions for bootloader and user app in conventional way using JSON file
diff --git a/docs/readme-mbed.md b/docs/readme-mbed.md
index 189c7bf..2162678 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/mcu-tools/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/main/boot/mbed/mbed_lib.json). Please note that certain features are not currently supported.
 
 ### Providing a secondary slot