docs(README): Replace --target with --function-target

[anishkny]

Otherwise it errors:

$ npx @google-cloud/functions-framework --target=helloWorld
Function 'function' is not defined in the provided module.
Did you specify the correct target function to execute?
Could not load the function, shutting down.

[grant]

Please create an issue before a PR.

It looks like we need to publish to npm for the README instructions to be correct.

You're looking at the previous version on npm. master in this repo has instructions that work when installing locally.

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We should publish the npm package after merging commits @swalkowski.

[anishkny]

Filed issue. Fixes #19

I was looking at README on master on GitHub here.

[stew-r]

We appreciate the issue & PR -- thanks for proactively finding a solution. Unfortunately, this is currently a mismatch between the (correct) docs and the latest version of our package. We're moving to 1.1.0 which replaces function-target with the shorter target CLI arg.

Based on that, I will close this PR.

[anishkny]

Sure no hard feelings. Just trying to help out 😉

[stew-r]

👍