[fix] Allow multiple files per concept set

Originates from Concepts #1

Enabling convertion of MELDB SAIL Phenotypes to acmc 0.1.12

• Update Validation Function + Type Checker
• Run Validation Command
• Update Map Function
• Run Map Command
• Add metadata (static dict per concept set)
• Add metadata flag to exclude metadata from output
• Run actions divide_col
• Run actions split_col
• Update Yaml Examples
• Update Diff Function
• Run Diff Command
• Add Non-translate Flag
• Fix PyTest
• Update Docs (index.md)