Adds new flag package using the stdlib, removing argparser as a dependency.
Fixed the github repo URL being wrong in the mod file and internal imports.
Reason for replacing akamensky/argparse:
This replaces a little used third party package with a frequently used library which only slightly extends the stdlib, and has been stable for years. This allows us to stay as close to the stdlib as possible, only extending where necessary. The new code should be much easier to grok and work with.
flagpackage using the stdlib, removing argparser as a dependency.Reason for replacing
akamensky/argparse: This replaces a little used third party package with a frequently used library which only slightly extends the stdlib, and has been stable for years. This allows us to stay as close to the stdlib as possible, only extending where necessary. The new code should be much easier to grok and work with.