feature/absolute value

[theiskaa]

Adds the absolute value functionality and updated error handling and errors.

Commits:

• feat: improve repl by adding token logger
• bugfix: fix sign-number reading issue of lexer
• hotfix: fix the calculator's index overflow issue
• feat: add index field to the token structure
• feat: improve current error cases
• feat: implement indexed errors
• hotfix: fix typo on changelog
• hotfix: rename the ROOT related actions to POWER
• feat: implement abs to token, tokentype, sub
• feat: improve the sub implementation to [token] and [monitor]
• feat: re-impl the abs [token-type] implementation
• feat: impl abs parsing to lexer
• feat: impl the abs calculator execution
• chore: update documentations