Positional parameters

[mmkal]

• Support positional parameters like migra postgresql://a psotgresql://b
• Also support numbers
• Also support booleans
• getInnerType helper to more accurately inspect zod schemas
• reorganise src dir into separate files rather than one 400+ line index.ts
• udpate calculator example to use positional parameters so calculator add 2 3 rather than calculator add --left 2 --right 3
• more hand-written docs on how flags and positional parameters work
• return ignoredProcedures instead of throwing when invalid
• add a validation test