Added markings to skinPromptPart.js

Description and notes

Merge Checklist

• I have read CONTRIBUTING.md
  • and
    • my code editor has
      • ESLint support enabled
      • TypeScript support enabled
      • some form of spell checker
        • We suggest using a spell checker compatible with cSpell if possible
    • my changes compile successfully and seem to work properly
    • I am using the simple compiler (simple-compiler.[bat or sh])
    • I am using the normal compiler (compile.[bat or sh])
    • this is my first merge request
    • the changes in this merge request comply with the coding style defined in CONTRIBUTING.md

Adding markings to SkinPromptPart to allow AI art to generate freckles and others in markings.

Changes made

• Some change
• Another change

Things left to do

• code review (this is done by one or more people other than you)
• final tests
• let Pregmodder know that this is ready for merging