Add mascot pattern generator

[LAieh12]

Fixes #134

Summary

• Add scripts/mascot_pattern.pl, a dependency-free Perl generator for mascot craft patterns.
• Support adjustable --banana, --goose, and --goblin motif ratios, yarn weight, craft type (crochet or knit), scale, and title.
• Document usage in the README.

Verification

• C:\Program Files\Git\usr\bin\perl.exe -c scripts/mascot_pattern.pl
• C:\Program Files\Git\usr\bin\perl.exe scripts/mascot_pattern.pl --banana 2 --goose 1 --goblin 1 --yarn-weight dk --craft crochet --name "Demo Mascot"
• C:\Program Files\Git\usr\bin\perl.exe scripts/mascot_pattern.pl --banana 0 --goose 3 --goblin 1 --yarn-weight worsted --craft knit --scale 1.25
• git diff --check

[prufrax]

This is looking good, but we need to support crafters all around the world. In particular, crocheters in the UK and USA are known to use the same terms but for completely different stitches, which can cause confusion! Add a parameter that selects which country's crafting terminology is used in the output document,

Given the existing push to add documentation in emoji elsewhere in the project - see issue #116 for details - we also need a parameter to select generating the output document using emojis instead of English.