linting errors in the markdown editor package

[Cronus1007]

Closes #52

Description

• The linting configs were not passed to the package and required a little bit of manual error detection
• It focusses upon resolving the linting errors in the package.

Screenshots or Video

Author Checklist

• Ensure you provide a DCO sign-off for your commits using the --signoff option of git commit.
• Vital features and changes captured in unit and/or integration tests
• Commits messages follow AP format
• Extend the documentation, if necessary
• Merging to master from fork:branchname
• Manual accessibility test performed
  • Keyboard-only access, including forms
  • Contrast at least WCAG Level A
  • Appropriate labels, alt text, and instructions

[Cronus1007]

@irmerk The PR completely doesn't solve the issue. For completion have a look upon this comment as well #52 (comment)

[jolanglinais]

I think linting should be handled from accordproject/techdocs#308 first.