Link Linux syscalls to their online manual pages

Signed-off-by: Nicola Squartini <tensor5@gmail.com>
Improve documentation about errors

Signed-off-by: Nicola Squartini <tensor5@gmail.com>
Improve description

Signed-off-by: Nicola Squartini <tensor5@gmail.com>
Bump version to 0.2.0.1

Signed-off-by: Nicola Squartini <tensor5@gmail.com>
Update CHANGELOG.md

Signed-off-by: Nicola Squartini <tensor5@gmail.com>