Update README.md to improve a document in pkg.go.dev

• Update README.md to improve a document in pkg.go.dev

Add more comments to improve a document in pkg.go.dev

• Add more comments to improve a document in pkg.go.dev
• Update GitHub actions
  • Change a name from go.yml to ci.yml
  • Add coverage action

Add more comments to improve a document in pkg.go.dev

• Add more comments to improve a document in pkg.go.dev

Edit package name from `convex` to `numconword`

• Edit package name from convex to numconword

v0.0.1: First release

Why create this?

This first release is a new version of my own number-to-words

Purpose

I focus on handling a big number than the previous version but still needs an improvement about the performance

Why is it slower than the previous version?

IMO, it's because of a decimal library that calculates a big number but if anyone thinks we could improve this, I welcome it.

Roadmap

• (WIP) Add GitHub actions, dependabot, and go doc
• Add more test cases
• Hack to improve a performance