Merge branch 'main' into glitch-soc/merge-upstream

Conflicts:
- `README.md`:
  Minor upstream change, our README is completely different.
  Kept ours.
- `lib/tasks/assets.rake`:
  glitch-soc has extra code to deal with its theming system,
  upstream changed a line that exists in glitch-soc.
  Applied upstream changes.

app/javascript/mastodon/features/compose/components/compose_form.js

@@ -243,6 +243,7 @@ class ComposeForm extends ImmutablePureComponent {
             id='cw-spoiler-input'
             className='spoiler-input__input'
             lang={this.props.lang}
+            spellCheck
           />
         </div>
 

app/javascript/mastodon/features/compose/components/poll_form.js

@@ -93,6 +93,7 @@ class Option extends React.PureComponent {
             maxLength={100}
             value={title}
             lang={lang}
+            spellCheck
             onChange={this.handleOptionTitleChange}
             suggestions={this.props.suggestions}
             onSuggestionsFetchRequested={this.onSuggestionsFetchRequested}