Update chumsky dependency to version 0.9.2

- Update the chumsky dependency in Cargo.toml from version 0.8.0 to version 0.9.2.
- Modify the comb.rs file to use the new whitespace() function instead of tokens::whitespace().repeated().
- Add a new whitespace() function that returns a parser for parsing whitespace tokens.
- Make other minor changes to improve code readability and maintainability.

This commit updates the chumsky dependency to version 0.9.2, modifies the comb.rs file, and adds a new whitespace() function for parsing whitespace tokens.