Automate creation of READMEs and example creation scripts

[ianthomas23]

Each example in this repo has both a README that is human-readable to manually create the example, and a create_* bash script to automatically create the example. Rather than keep these as two separate files which will diverge in time, here I am adding TypeScript code in the new recipes directory to create both files from a single source. Each example will have its own recipe (e.g. vanilla_webpack_recipe.ts) consisting of multiple steps, and the READMEs and scripts can be regenerated using

cd recipes
npm install
npm run build
npm run create

This can be run manually as required and the diffs inspected before committing.