add generic mark toggle to marking formats

[possumbilities]

Description

• Fixes Provide generic Mark Your Work without Attribution details #574
• adds a new toggle to each marking format to instead display a "generic mark".

Technical details

This amends the output logic for all three marking formats (Rich Text, HTML, Plain Text) to check for the status of the "generic mark" checkbox toggle. If the box is checked the format will display as follows:

Unchecked (default)

Untitled © 1999 by Jane Doe is licensed under CC BY 4.0. To view a copy of this license, visit https://creativecommons.org/licenses/by/4.0/

Checked

This work is licensed under CC BY 4.0. To view a copy of this license, visit https://creativecommons.org/licenses/by/4.0/

Tests

1. navigate here: https://deploy-preview-607--creativecommons-chooser.netlify.app/
2. fill out the chooser
3. see marking formats section
4. check the generic mark toggle
5. see results.

Checklist

• My pull request has a descriptive title (not a vague title like Update index.md).
• My pull request targets the default branch of the repository (main or master).
• My commit messages follow best practices.
• My code follows the established code style of the repository.
• I added or updated tests for the changes I made (if applicable).
• I added or updated documentation (if applicable).
• I tried running the project locally and verified that there are no
  visible errors.

Developer Certificate of Origin

For the purposes of this DCO, "license" is equivalent to "license or public domain dedication," and "open source license" is equivalent to "open content license or public domain dedication."

Developer Certificate of Origin

Developer Certificate of Origin
Version 1.1

Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
1 Letterman Drive
Suite D4700
San Francisco, CA, 94129

Everyone is permitted to copy and distribute verbatim copies of this
license document, but changing it is not allowed.


Developer's Certificate of Origin 1.1

By making a contribution to this project, I certify that:

(a) The contribution was created in whole or in part by me and I
    have the right to submit it under the open source license
    indicated in the file; or

(b) The contribution is based upon previous work that, to the best
    of my knowledge, is covered under an appropriate open source
    license and I have the right under that license to submit that
    work with modifications, whether created in whole or in part
    by me, under the same open source license (unless I am
    permitted to submit under a different license), as indicated
    in the file; or

(c) The contribution was provided directly to me by some other
    person who certified (a), (b) or (c) and I have not modified
    it.

(d) I understand and agree that this project and the contribution
    are public and that a record of the contribution (including all
    personal information I submit with it, including my sign-off) is
    maintained indefinitely and may be redistributed consistent with
    this project or the open source license(s) involved.

[netlify]

✅ Deploy Preview for creativecommons-chooser ready!

Name	Link
🔨 Latest commit	53fe379
🔍 Latest deploy log	https://app.netlify.com/projects/creativecommons-chooser/deploys/68cd8490c9d9930008c46466
😎 Deploy Preview	https://deploy-preview-607--creativecommons-chooser.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.