nuts-and-bolts: minor fixes

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
ubuntu: "sources" -> "repository types"

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
opensuse: fix English

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
enterprise: english Fix + add dist examples

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
archlinux: fix English

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
getting-started: add "investigate"

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
tracing-the-linux-kernel: minor fixes

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
tracing-your-own-user-application: add details

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>