Bug 1614919 browser.identity.launchWebAuthFlow() exposes redirect_url (#12016)
Bug 1614919 browser.identity.launchWebAuthFlow() exposes redirect_url (#12016)

* Bug1614919 browser.identity.launchWebAuthFlow() exposes redirect_url

Added notes to:
* getRedirectURL regarding the use of a loopback address
* launchWebAuthFlow  noticing the need for redirect_uri to be set to the URL returned by identity.getRedirectURL()

* Addressed feedback about level of detail in note

* Addressed feedback changes:
* move new note to launchWebAuthFlow
* amended required note to optional from 63 to resolve rendering issue
* moved details of redirect_uri to separate line

Co-authored-by: Richard Bloor <b757ed502e9cd53032b93a1a07cebbdf1c211aaa@atlassian.com>
mdn/browser-compat-data,chrisdavidmills/browser-compat-data,mdn/browser-compat-data,chrisdavidmills/browser-compat-data