Document changes and release 5.13.19pureos2~amber1 of linux-librem5

Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm>
2 jobs for release51319_2_amber in 72 minutes and 37 seconds
latest
Status Job ID Name Coverage
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passed #369748
librem5
build:aarch64

00:24:31

passed #369749
librem5:arm64
build:deb

01:12:37