FreeRTOS-Plus-TCP Library V4.2.1

FreeRTOS-Plus-TCP Library V4.2.0

FreeRTOS-Plus-TCP Library V4.1.1

FreeRTOS-Plus-TCP Library V4.1.0

FreeRTOS-Plus-TCP Library V4.0.0

FreeRTOS-Plus-TCP Library V4.0.0-appsec

FreeRTOS-Plus-TCP Library V4.0.0-rc3

FreeRTOS-Plus-TCP Library V4.0.0-rc2

FreeRTOS-Plus-TCP Library V4.0.0-rc1

Update README to add link to LTS 2.0 release.