v2.1.0

This is a minor update right before another important update about Taiwan Resident Certificate.

• New: Add ESM distribution, so you can import individual module(s) as you need. Please see the <esm/>.
• Fix: Node 12+ import error by changing file extension of ESM files. Please see the directory <bundles/>.

⚠️ Important: For existing developers, please check your import statements about ESM bundle files:

• ❌ Wrong: 'validid/bundles/validid.esm(.min).js'
• ✅ Correct: 'validid/bundles/validid.esm(.min).mjs'

Other things:

• In <src/>, add back ".coffee" file extension in all import statements.
• Take out isLengthValid() in all ID modules. Suppose they are used for returning Error object, but they are useless right now.
• Add "is-twid-checksum-valid" module that will be useful in next update.
• Start using Gulp for building ESM and clean up processes.
• Highly recommend to develop this package using Node 14 LTS. (Developers can use lower Node version to "consume" this package, tho.)
• Update and improve a lot of things in development experience. Please see the files in root directory.