Fix broken links and format markdown

[fel1x-developer]

https://github.com/jmmv/atf and https://github.com/jmmv/kyua are redirected to repos that belong to FreeBSD organization account.

[ngie-eign]

Hi @fel1x-developer ! Could you please add "Signed-off-by" to your commits and maybe elaborate a bit more about what is being done? FWIW, I'd be tempted to squash your commits as-is since they are bulletpoints in a common theme of changes.

[fel1x-developer]

Finished elaborating commit messages