Get rid of settings file entrypoint assumption in core

[JasonYao]

Background

• feat(developer environments): Adds in the ability to install language runtimes and venvs #65 introduced developer environments, the use of a common schema shared between other schemas, and most importantly a change in the validator to validate all .json/.yaml/.yml files by default.
• This means two things:
  • We are no longer tied to settings.yaml/json/yml as the entrypoint for a module. This should be reflected in docs and examples
  • We are able to run multiple files in a given directory
    • This means either that we need multiple Module objects, or for each file create a Module object

Tasks

• Validator: Get rid of default_settings_file in alpha.core schema
• Core: Get rid of the logic isolating for settings.yaml/json/yml, and replace with a tree walk (Normalize file loading #71)
• Validator -> Core: Migrate the logic where the files are chosen from the validator to pydotfiles.common or someplace else, and then have both core and the validator call this (Normalize file loading #71)
• Add in a test that has a random json file in there somewhere- we should not end up validating the json file in that case (Add in support for file ignoring #72)
  • One approach here would be to add in support for ignoring certain files. Maybe adding in support for a .pydotfilesignore file?