Change shorthand --enable-type flag to avoid typo

[font]

What this PR does / why we need it:
The --enable-type long option can be accidentally typed with only 1 - as in -enable-type resulting in the following error:

$ kubefedctl federate secret kubefed -enable-type
F0809 15:24:48.160303   17400 federate.go:150] Error: Error retrieving target Secret "able-type/kubefed": secrets "kubefed" not found

The error occurs because combined shorthand options as in -en are valid. If a shorthand option takes an argument, as in -n, it must be the last argument, so it interprets the rest of the command able-type as the namespace argument. This can be confusing and is only a special case because e and n are both shorthand flags while their combined use spells out the long form of an option.

This fixes that by changing the shorthand flag for --enable-type to -t instead of -e.

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

Special notes for your reviewer:

[k8s-ci-robot]

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This pull-request has been approved by: font

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[xunpan]

@font
The shorthand of other related options are the first charactor of the long name for easy memorized.
What about change the long name to make it consistent with others?
e.g. s/enable-type/type-enabled/

[font]

The shorthand of other related options are the first charactor of the long name for easy memorized.
What about change the long name to make it consistent with others?
e.g. s/enable-type/type-enabled/

@xunpan Yes, that's the downside i.e. the shorthand letter is not the first character of the long name. Thanks for the suggestion. I think it's preferable to stick with enable-type instead of type-enabled. The alternative is to not allow a shorthand letter at all, but I thought a shorthand option might be preferable, even if it isn't the first letter of the long name.

[abhat]

The shorthand of other related options are the first charactor of the long name for easy memorized.
What about change the long name to make it consistent with others?
e.g. s/enable-type/type-enabled/

@xunpan Yes, that's the downside i.e. the shorthand letter is not the first character of the long name. Thanks for the suggestion. I think it's preferable to stick with enable-type instead of type-enabled. The alternative is to not allow a shorthand letter at all, but I thought a shorthand option might be preferable, even if it isn't the first letter of the long name.

Yeah, agree with @font - the verb-noun form is more intuitive and consistent IMO. But good suggestion nevertheless @xunpan.

[abhat]

/lgtm

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[xunpan]

It is not a mandatory change but suggestion. I'm ok with your comments.

LGTM

[pmorie]

/lgtm