Clarify SPEC discussion URLs

[stefanv]

Status quo

Currently, the SPEC Purpose & Process says:

• Each SPEC has a corresponding discussion with the same title, where anyone can comment, ask questions, or vote on existing comments.

Later:

• Before a proposed SPEC can be accepted, the idea must be discussed on the discussion forum under the SPECS/Ideas topic.

We therefore, currently, have three potential to discuss a SPEC: under SPECS/Ideas, under SPECS/Accepted (Jarrod's been moving SPECS/Ideas to SPECS/Accepted by hand), and under SPECS/Web Comments.
The first (SPECS/Accepted) is pointed to in the header of the SPEC, and the latter is what is embedded below the SPEC on scientific-python.org.

Proposal

We reduce the number of topic categories to two: SPECS/Ideas and SPECS/Web Comments. These serve orthogonal purposes: the first is to figure out whether a SPEC is a good idea, discuss with the proposer how to write the SPEC, etc. This discussion is typically somewhat noisy and technical, and it discusses many things outside of the scope of the SPEC.

Once the SPEC appears on the website (and we should decide whether this means as DRAFT or Published), it is ready for community feedback. These comments are related to the SPEC idea, will be embedded below the SPEC, and will go to SPECS/Web Comments.

Details

• Remove header link to the originating SPECS/Ideas discussion from SPECs on scientific-python.org
• Embedding in Discourse is a tad magical, so while embedded comment topics are auto-created, we can only find them after-the-fact. Figure out how to put a link in place in the header, via JS or whatnot, that redirects to SPECS/Web Comments topic.
• Update the SPEC Purpose and Process to match whatever we decide on here.
• Update the SPEC template to no longer have a discussion field.
• Move all SPECS/Accepted posts back to SPECS/Ideas. We could even consider removing those subcategories, so we only have SPECS and SPECS/Web Comments.

Other ideas welcome!

[stefanv]

See the above linked PRs.