A poster on our forum observed that the accuracy of our LDPC decoder
was very much worse than that of other implementations.

The cause is that we do all our calculations in int8_t fixed-point,
which quickly saturates. The fix is to do all intermediate
calculations in int16_t fixed-point.

On average this causes a performance regression of between 1.2x and
1.3x across all ArmRAL benchmarks.

Co-Authored-By: Radu Salavat <radu.salavat@arm.com>
Co-Authored-By: Rosie Sumpter <rosie.sumpter@arm.com>
Co-Authored-By: Amy Wignall <amy.wignall@arm.com>

Co-Authored-By: Nick Dingle <nick.dingle@arm.com>
Co-Authored-By: Amy Wignall <amy.wignall@arm.com>
Co-Authored-By: Radu Salavat <radu.salavat@arm.com>

Co-Authored-By: Rosie Sumpter <rosie.sumpter@arm.com>
Co-Authored-By: Ryo Suzuki <ryo.suzuki@arm.com>

This will allow Gitlab to automatically detect it and link to it from
the front page of the project, which will make it more visible to
users.

Also update the list of third party licenses (currently empty) to
match and update the documentation to point to the new license files.

This collates all the change information from the Release Notes for
all releases into a single document. Subsequent releases will have
this information added in future.

We also update the Merge Request templates to tell contributors to
update the Changelog.