PURL-SPECIFICATION.rst is obsolete

[mjherzog]

As of August 13, 2025 - PURL-SPECIFICATION.rst is obsolete. The content was moved to a new set of markdown files with #589. The reason was to prepare for the publication of the Ecma standard where we have some content shared between the spec and the standard, some content only in the standard and some content only in the spec.

If you have an in-flight issue or PR referencing PURL-SPECIFICATION.rst, please update it to refer to the new file or files. The following table provides a mapping by line numbers from PURL-SPECIFICATION.rst to the new markdown files:

PURL-SPECIFICATION.rst Line numbers	Section title(s)	included in Ecma Standard document?	New markdown file
1-109	What is a purl? Some purl examples A purl is a URL	Yes	/docs/standard/summary.md
112-229	Rules for each purl component	Yes	/docs/standard/components.md
232-300	Permitted characters purl separators Character encoding Case folding	Yes	/docs/standard/characters-and-encoding.md
302-374	How to build a purl string from its components	No	/docs/how-to-build.md
377-454	How to parse a purl string int its components	No	/docs/how-to-parse.md
457-461	Registered purl types	No	/docs/types.md
463-509	Known qualifier key/value pairs	No	/docs/known-qualifiers.md
512-544	Tests	No	/docs/tests.md