Add tkl_f13_ansi_tsangan community layout to novelkeys/nk87*

[arcmags]

Description

The proper LAYOUTS variable was added to rules.mk for novelkeys/nk87 keyboards. These changes are necessary to easily compile corresponding keymaps in layouts/community/.

Sources

• NovelKeys NK87

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Keyboard (addition or update)
• Keymap/layout (addition or update)
• Documentation

Checklist

• My code follows the code style of this project: C, Python
• I have read the PR Checklist document and have made the appropriate changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).

[waffle87]

This change should be made in the keyboard.json file under the community_layouts key.