[lighthouse] add "mixed content" reference

[kaycebasques]

What's changed, or what was fixed?

• adds reference for the "mixed content" audit

Fixes: N/A

Target Live Date: 2018-02-08

• This has been reviewed and approved by @kaycebasques (myself)
• I have run gulp 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: @petele

[WebFundBot]

👍

[WebFundBot]

🎉 This has been pushed live to https://developers.google.com/web/

[christhompson]

With GoogleChrome/lighthouse#4441, we'll have a clean way to invoke the new audit. @paulirish thinks it would be best to add the "how to run this audit" section to the existing docs here (see GoogleChrome/lighthouse#4444). I'd suggest something along the lines of:

How to use this audit

This audit is not run by default in Lighthouse, and currently requires that you have Chrome Canary installed. To use it, you will need to run the lighthouse command-line tool. You can install lighthouse using npm:

npm install -g lighthouse

To run the audit, you can use the included --mixed-content flag:

lighthouse --mixed-content http://www.example.com

This will create a new HTML Lighthouse report file in your current working directory.

---

I'd be happy to make a quick PR to add that, if you'd like.

[christhompson]

Should the figures be numbered 1/2/etc. for the final version?

[christhompson]

I drafted a quick PR with the potential additional docs #5764. Let me know what you think.