The goal of this directory is to gather all the "interfaces" used
by the different semgrep components:
 - the semgrep-core program
 - the pysemgrep CLI

We're using atdgen to specify the types of most of those interfaces.
See https://github.com/ahrefs/atd for more information on atdgen.

We're also using jsonschema for rule_schema_v1.yaml (JSON schemas
can also be specified using a YAML syntax, and they can also
be used to check the schema of YAML files).
