Announce: RTEMS 5.3 Release

[Chris Johns]

RTEMS 5.3 Release is available.

 https://ftp.rtems.org/pub/rtems/releases/5/5.3

Please follow the release instructions provided by the link.

We love to hear about your projects and what you use RTEMS on so please let us
know. You can drop by on Discord, post on user at rtems.org or you can send Joel or
me a private email.

If you find a problem please raise a ticket and select the 5.4 milestone. The
simplest way to create a ticket is to head to the developer Wiki at:

 https://devel.rtems.org/

Then click on the "Next (milestone)" link for the RTEMS 5 Release. You will need
an account.

Thanks
Chris