style(text-editor): overriding default mde styles

[owilliams320]

Description

Style adjustment for text editor component to respect the light/dark themes

Test Steps

• [ ] npm run start
• [ ] then navigate to the text component documentation
• [ ] finally toggle themes to ensure the text component is visually changing

General Tests for Every PR

• [ ] npm run start still works.
• [ ] npm run lint passes.
• [ ] npm run stylelint passes.
• [ ] npm test passes and code coverage is not lower.
• [ ] npm run build still works.

Before

After

[owilliams320]

:tada: This PR is included in version 8.9.1 :tada:

The release is available on:

• v8.9.1
• GitHub release

Your semantic-release bot :package::rocket: