We used a hard-coded list of capabilities that we copied from containerd,
but the new "capability" package allows use to have a maintained list
of capabilities.
There's likely still some improvements to be made;
First of all, the capability package could provide a function to get the list
of strings.
On the completion-side, we need to consider what format is most convenient;
currently we use the canonical name (uppercase and "CAP_" prefix), however,
tab-completion is case-sensitive by default, so requires the user to type
uppercase letters to filter the list of options.
Bash completion provides a `completion-ignore-case on` option to make completion
case-insensitive (https://askubuntu.com/a/87066), but it looks to be a global
option; the current cobra.CompletionOptions also don't provide this as an option
to be used in the generated completion-script.
Fish completion has `smartcase` (by default?) which matches any case if
all of the input is lowercase.
Zsh does not have a dedicated option, but allows setting matching-rules
(see https://superuser.com/a/1092328).
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
