Local check spelling

What's Changed

• Documentation by @ChrisPrusik in #1
• Update README.md by @ChrisPrusik in #2
• Command line switch --help is available now by @ChrisPrusik in #3
• Command line description in the README.md by @ChrisPrusik in #4
• Local check spelling, refactor and docs by @ChrisPrusik in #5
• Ignore spelling words file #6

Full Changelog: v3...v4