Update the readme

[peternewman]

Add all the new options that are in the action.yml file

[peternewman]

Better yet, find or make a simple way to auto-update them given they have descriptions.

[peternewman]

Mustache can't do this as it can't get the keys out, Handlebars can, but we'd have to use yq or something to convert the YAML to JSON first: https://handlebarsjs.com/playground.html#format=1&currentExample=%7B%22template%22%3A%22%23%20%7B%7Bname%7D%7D%5Cn%7B%7Bdescription%7D%7D%5Cn%7B%7B%23each%20inputs%7D%7D%5Cn%5Cn%23%23%23%20Parameter%3A%20%7B%7B%40key%7D%7D%5Cn%7B%7Bthis.description%7D%7D%5Cn%7B%7B%2Feach%7D%7D%22%2C%22partials%22%3A%5B%5D%2C%22input%22%3A%22%7B%5Cn%20%20name%3A%20'Codespell%20with%20annotations'%2C%5Cn%20%20description%3A%20'Codespell%20with%20annotations%20for%20Pull%20Request'%2C%5Cn%20%20inputs%3A%20%7B%5Cn%20%20%20%20'check_filenames'%3A%20%7B%5Cn%20%20%20%20%5Ctdescription%3A%20%5C%22foo%5C%22%5Cn%20%20%20%20%7D%2C%5Cn%20%20%20%20'check_bar'%3A%20%7B%5Cn%20%20%20%20%5Ctdescription%3A%20%5C%22bar%5C%22%5Cn%20%20%20%20%7D%2C%5Cn%20%20%7D%2C%5Cn%7D%5Cn%22%2C%22output%22%3A%22%23%20Codespell%20with%20annotations%5CnCodespell%20with%20annotations%20for%20Pull%20Request%5Cn%5Cn%23%23%23%20Parameter%3A%20check_filenames%5Cnfoo%5Cn%5Cn%23%23%23%20Parameter%3A%20check_bar%5Cnbar%5Cn%22%2C%22preparationScript%22%3A%22%2F%2F%20Handlebars.registerHelper('loud'%2C%20function(string)%20%7B%5Cn%2F%2F%20%20%20%20return%20string.toUpperCase()%5Cn%2F%2F%20%7D)%3B%5Cn%22%2C%22handlebarsVersion%22%3A%224.7.7%22%7D