Changes

• feat: new option --json to format output as JSON array
• feat: -r can be used when cutting --characters. It replaces the (empty) delimiter between characters with whatever you provided
• feat: exit early when some combinations of fields cannot be used together
• feat: updated dependencies. In particular the regex crate which offers new functionalities (word boundary assertions)
• fix: field formatting is now applied to field 1 even if no delimiters are found (similar to how we print the unformatted field 1)
• doc: many error messages have been rewritten for better clarity
• doc: new svg demo in the README