Reorganize paperspec commands and pin dependency versions (#2)

Reviewed-on: #2

docs/comparison.md

@@ -428,8 +428,8 @@ Keep using it as a reading and distribution format.
 *Status.*
 The specification is version 0.1.0.
 `registry/formats.json` lists 32 formats: 19 are `candidate` (complete, with vectors and fixtures, ready to implement) and 13 are `provisional` (complete; expected to change as implementations gain experience): project, bundle, dataset, digitization, view, snapshot, draft-ids, exercise, submission, grade, checklist, log-entry and checkpoint ([spec/00 §0.4](../spec/00-introduction.md#04-status)).
-The repository holds 24 chapters, 42 JSON Schemas, 25 vector files, five valid fixture packages, one of them also zipped, and 31 invalid ones, each naming the rule it breaks, and a reference checker, `tools/check.py`.
-Licenses: prose CC BY 4.0; schemas, SQL, the JSON-LD context, registries, vectors and fixtures CC0 1.0; tools Apache-2.0 ([README.md](../README.md#licenses)).
+The repository holds 24 chapters, 42 JSON Schemas, 25 vector files, five valid fixture packages, one of them also zipped, and 31 invalid ones, each naming the rule it breaks, and a reference checker, `paperspec check`.
+Licenses: prose CC BY 4.0; schemas, SQL, the JSON-LD context, registries, vectors and fixtures CC0 1.0; the code in `src/` Apache-2.0 ([README.md](../README.md#licenses)).
 
 *No adoption claim.*
 The repository names no outside adopter and no independent implementation, and this page claims none.