Merge commit '55e7c08a83547424024bac311d5459cb82cf6dae' into glitch-soc/merge-upstream

Conflicts:
- `app/models/user_settings.rb`:
  Upstream added a constraint on a setting textually close
  to glitch-soc-only settings.
  Applied upstream's change.
- `lib/sanitize_ext/sanitize_config.rb`:
  Upstream added support for the `translate` attribute on a few elements,
  where glitch-soc had a different set of allowed elements and attributes.
  Extended glitch-soc's allowed attributes with `translate` as upstream did.
- `spec/validators/status_length_validator_spec.rb`:
  Upstream refactored to use RSpec's `instance_double` instead of `double`,
  but glitch-soc had changes to tests due to configurable max toot chars.
  Applied upstream's changes while keeping tests against configurable max
  toot chars.

app/javascript/mastodon/features/home_timeline/components/explore_prompt.jsx

@@ -0,0 +1,24 @@
+import React from 'react';
+
+import { FormattedMessage } from 'react-intl';
+
+import { Link } from 'react-router-dom';
+
+import background from 'mastodon/../images/friends-cropped.png';
+
+import DismissableBanner from 'mastodon/components/dismissable_banner';
+
+
+export const ExplorePrompt = () => (
+  <DismissableBanner id='home.explore_prompt'>
+    <img src={background} alt='' className='dismissable-banner__background-image' />
+
+    <h1><FormattedMessage id='home.explore_prompt.title' defaultMessage='This is your home base within Mastodon.' /></h1>
+    <p><FormattedMessage id='home.explore_prompt.body' defaultMessage="Your home feed will have a mix of posts from the hashtags you've chosen to follow, the people you've chosen to follow, and the posts they boost. It's looking pretty quiet right now, so how about:" /></p>
+
+    <div className='dismissable-banner__message__actions'>
+      <Link to='/explore' className='button'><FormattedMessage id='home.actions.go_to_explore' defaultMessage="See what's trending" /></Link>
+      <Link to='/explore/suggestions' className='button button-tertiary'><FormattedMessage id='home.actions.go_to_suggestions' defaultMessage='Find people to follow' /></Link>
+    </div>
+  </DismissableBanner>
+);