Modified a few things:

- Finished implementing relative date parsing and migrated date parsing
  from Flag(T) to it's own dedicated module. Additionally added a
  the ability to do "recursive" relative operations for time searching.
- Additionally made a Struct & Enum for containing relative operations
  around dates.
- Added additional checks in App & CommandNode(T) around checking
  env_vars of flags & checking for duplicate commands
- Added a CommandMeta record to contain the classname of the
  CommandNode(T)
- Seperated out all of the monolitic files (command_node.cr & file.cr).
  Moved the base classes and records into their own files in the dir
  with the same name of their generic counterparts.
- Fixed a number of macro related bugs around Command.argument &
  CliGen.add_global_flag
- My ass hurts from sitting here for hours and doing these changes and
  arguing with claude over what needs to be done. Fun tho.

.gitignore

@@ -6,10 +6,16 @@
 !src/**
 !shard.yml
 !README.md
-!design.adoc
+!DESIGN.md
 !docs/
 !docs/**
 !Makefile
 !LICENSE
+!NOTICE
 !spec/
 !spec/**
+!utils/
+!utils/**
+
+# ...but not the binary utils/flag_matrix.sh builds (later rules win).
+utils/flag_matrix