Update Workbox "Using Plugins" documentation

[housseindjirdeh]

What's changed, or what was fixed?

• Updates the "Using Plugins" documentation for Workbox to include new plugin capabilities:
  • Lifecycle state
  • New lifecycle callbacks

Target Live Date: TBD

• This has been reviewed and approved by (NAME)
• I have run npm test locally and all tests pass.
• I have added the appropriate type-something label.
• I've staged the site and manually verified that my content displays correctly.

CC: @jeffposnick @philipwalton

[jeffposnick]

Thanks for doing this!

As with the other content that targets Workbox v6, we're going to hold off on merging until we've released v6.0.0.

[jeffposnick]

I don't think there's a meaningful distinction between these "lifecycle callbacks" and the other group of existing callbacks. All of the callbacks in this section are new for v6 and are tied to the handler* lifecycle, but conceptually, they're very similar to the existing callbacks and should probably be listed alongside them.

Would you mind rearranging things so that these aren't broken out into their own section? You can add in something like "The lifecycle callbacks starting with handler are all new in Workbox v6." to make it clear what the support story is.

[housseindjirdeh]

Updated, and added a note mentioning how handler callbacks are new in v6 :)

[WebFundBot]

Whoops!

There were 4 warnings that will prevent this PR from being merged. Please take a look, and either fix, or provide a justification for why they can't be fixed.

WARNINGS
src/content/en/tools/workbox/guides/using-plugins.md#L221 - Consider adding a "was this page helpful?" widget to your page: https://developers.google.com/web/resources/widgets#helpful
src/content/en/tools/workbox/guides/using-plugins.md#L47 - Common typo found: 'javascript' Should it be 'JavaScript'?
src/content/en/tools/workbox/guides/using-plugins.md#L124 - Common typo found: 'javascript' Should it be 'JavaScript'?
src/content/en/tools/workbox/guides/using-plugins.md#L111 - Common typo found: 'ServiceWorker' Should it be 'service worker'? Capitalize Service if it's the first word in the sentence.

[petele]

@jeffposnick - can you take a peek and LGTM/merge?