jsonschema: fix link block in package doc

One entry is missing a colon, without which, not only is the one link
not valid, the entire section is considered invalid and none of the link
references are used.

Another link uses a different name for declaration and use.

Change-Id: I6a6a636c54e37ef60c0b52b1030f68e63d4ee68a

Author: prattmic

jsonschema/doc.go

@@ -94,8 +94,8 @@ are recorded in the schema, but ignored during validation.
 [JSON Schema specification]: https://json-schema.org
 [section 7 of the validation spec]: https://json-schema.org/draft/2020-12/draft-bhutton-json-schema-validation-00#rfc.section.7
 [section 8 of the validation spec]: https://json-schema.org/draft/2020-12/draft-bhutton-json-schema-validation-00#rfc.section.8
-[learnjsonschema.org]: https://www.learnjsonschema.com/2020-12/format-annotation/format/
-[this table of differences] https://github.com/dlclark/regexp2?tab=readme-ov-file#compare-regexp-and-regexp2
+[learnjsonschema.com]: https://www.learnjsonschema.com/2020-12/format-annotation/format/
+[this table of differences]: https://github.com/dlclark/regexp2?tab=readme-ov-file#compare-regexp-and-regexp2
 [annotations]: https://json-schema.org/draft/2020-12/json-schema-core#name-annotations
 */
 package jsonschema