fix: maintain require() compatibility for filters

[colinrotherham]

This fix addresses an issue raised on Slack

I've added a workaround to keep the moj/filters/all export working whilst we look at:

• docs: fix example require path to Nunjucks filters #1249

Module resolution

For example, Node.js can't resolve moj/filters/all

node --eval "console.log(require.resolve('@ministryofjustice/frontend/moj/filters/all'))"

But it can resolve moj/filters/all.js

node --eval "console.log(require.resolve('@ministryofjustice/frontend/moj/filters/all.js'))"

This is caused by both Package entry point "exports" in package.json and Node.js mandatory file extensions

Outdated examples

Both of these examples will need updating in #1249

moj-frontend/src/moj/components/messages/README.md

Line 11 in a909349

let mojFilters = require('./node_modules/@ministryofjustice/frontend/filters/all')();

moj-frontend/src/moj/components/timeline/README.md

Line 11 in a909349

let mojFilters = require('./node_modules/@ministryofjustice/frontend/filters/all')();