Update links to schema.rb

This has been made public, as per #603

Author: pezholio

docs/adding_a_new_schema.md

@@ -10,7 +10,7 @@ in a JSON schema format.
 This represents the shape of the data which will be stored in a content block's `details` field.
 
 Once the schema is defined, you must define it as a supported schema in the
-[`VALID_SCHEMAS` constant within the Schema class](https://github.com/alphagov/content-block-manager/blob/main/app/models/schema.rb#L4)
+[`VALID_SCHEMAS` constant within the Schema class](https://github.com/alphagov/content-block-manager/blob/main/app/public/models/schema.rb#L4)
 so that it can be used in Content Block Manager.
 
 Schemas can be defined as `live` or `alpha`. `live` schemas are visible in production, and can be accessed by anyone.

docs/schemas.md

@@ -4,7 +4,7 @@
 
 All content block types are managed in the schemas within the [Schema definitions directory](https://github.com/alphagov/content-block-manager/tree/main/app/models/schema/definitions).
 
-Schemas are picked up by Content Block Manager via the [`Schema` class](https://github.com/alphagov/content-block-manager/blob/main/app/models/schema.rb).
+Schemas are picked up by Content Block Manager via the [`Schema` class](https://github.com/alphagov/content-block-manager/blob/main/app/public/models/schema.rb).
 
 When creating a new content block, we fetch all the supported schemas and give the user a list of valid block types to
 create. Once a block type is chosen the form is then populated using all the fields within a schema's `details` object