Added Handlebars implementation

[RayyanNafees]

Description

Handlebars says itself to be "Mustache compatible" on their website but its implementation with HTMX client-side-template extension is slightly different and breaks when migrating to Handlebars from Mustache

I've added the Different implementation from mustache, needed to be followed when using handlebars

Significantly two explicit changes are needed

1. Use the CDN upkg.com /handlebars@latest/dist/handlebars.min.js instead of /handlebars@latest
2. Use {#each this} for looping instead of {#each data} or {#data} inspired from mustache example

Corresponding issue:

Checklist

• [x] I have read the contribution guidelines
• [x] I have targeted this PR against the correct branch (master for website changes, dev for source changes)
• [x] This is either a bugfix, a documentation update, or a new feature that has been explicitly approved via an issue
• [x] I ran the test suite locally (npm run test) and verified that it succeeded