chore!: Normalize repository, dropping node <10.13 support

[sttk]

This PR updates this project:

• Updates dependency versions
• Updates GitHub Actions files
• Adds, changes and deletes some project files
• Drops arr-filter, array-map, array-each, array-initial, and array-last from dependencies.
  • arr-flatten is left because Array#flat is introduced in Node.js v11.

NOTE: Be careful that this package depends on async-done, async-settle and now-and-later that will be bumped up.

[sttk]

@phated I've dropped arr-flatten and implements alternate code.

[sttk]

@phated I've modified what you pointed out.