[DevToolbar] Create new docs pages for the Toolbar

[ryan953]

Port this doc into markdown and put it up on the docs site:
https://docs.google.com/document/d/1O5n00DVNWzEG01J5ZkRdnBwG_J-Lo9jtguodYTALzd0/edit?tab=t.0

That includes taking the needed screenshots.

[ryan953]

To inject the toolbar into 'random' sites use this snippet:

Paste the following into the console:
1.
var s = document.createElement('script');
s.src = "https://browser.sentry-cdn.com/sentry-toolbar/latest/toolbar.min.js";
document.head.appendChild(s);
2.
window.SentryToolbar.init({ mountPoint: document.body,sentryOrigin: 'https://demo.sentry.io', region: 'us', sentryApiPath: '/api/0', featureFlags: null, organizationSlug: 'demo', projectIdOrSlug: 'react', environment: 'production', domId: 'sentry-toolbar', placement: 'right-edge', theme: 'light'});

note that this does not include set up for the feature flag panel

Also remember to edit the Project Settings > Dev Toolbar in sentry.io to allow the domain that the webapp uses!