Update docs

[erikyo]

In this PR we are going to update

• Readme replaces require (cjs) with import (esm), adds installation instruction
• package.json - version update according to semver
• CHANGELOG.md - annotate changes before release the new version

ref. #86

[erikyo]

this shield should be added to the repository (it's useful as a link to the npmjs website)

[erikyo]

bundlephobia reports a strange data about gettext-parser metadata. maybe something in the package json wasn't correct in the last version?
https://bundlephobia.com/package/[email protected]

a similar repo weights 100 times less! What is causing the bloat? (cit @johnhooks)
https://bundlephobia.com/package/[email protected]

[johnhooks]

We suspect it calculates the dependencies in the bundle size.