docs: Fix grammar of mat view WITH options

[ggevay]

Fixes two issues with the grammar diagram of CREATE MATERIALIZED VIEW:

• It looked as if WITH () (i.e., empty parens after WITH) would be possible.
• It looked as if ASSERT NOT NULL and RETAIN HISTORY can come only in this order, but actually ASSERT NOT NULL can be specified also after RETAIN HISTORY (even both before and after).

Note that the new diagram is also not perfect, because now it looks as if RETAIN HISTORY could be specified more than once. I think we have to accept this, because it seems impossible to exactly specify using BNF that these options can be specified in any order, and ASSERT NOT NULL can be specified any number of times, but RETAIN HISTORY can only be specified once. I think it's ok that we are not capturing certain restrictions in the grammar diagram, especially if they are handled by planning and not by parsing. (For example, it's also impossible to capture that ASSERT NOT NULL can't be specified for the same column twice.)

Also, the new layout seems cleaner overall, especially when I add REFRESH soon.

Note that I did not add the optional = for ASSERT NOT NULL. Started a discussion on this here:
https://materializeinc.slack.com/archives/C063H5S7NKE/p1716888019218749

Plus the commit removes a stale PrPr notice fragment for ASSERT NOT NULL.

Next I'm going to work on adding REFRESH, but I'd like to get an opinion on the above before I get too deep into the REFRESH grammar.

Motivation

Fixes minor docs issues.

Tips for reviewer

Checklist

• This PR has adequate test coverage / QA involvement has been duly considered. (trigger-ci for additional test/nightly runs)
• This PR has an associated up-to-date design doc, is a design doc (template), or is sufficiently small to not require a design.
• If this PR evolves an existing $T ⇔ Proto$T mapping (possibly in a backwards-incompatible way), then it is tagged with a T-proto label.
• If this PR will require changes to cloud orchestration or tests, there is a companion cloud PR to account for those changes that is tagged with the release-blocker label (example).
• This PR includes the following user-facing behavior changes:

[ggevay]

Cherry-picked @arusahni's commit from here to make the hugo build work on newer hugo. It works for me now on hugo v0.126.3.

[def-]

No complaints from QA side

[ggevay]

CI is failing in "Lint docs" for some reason:
https://buildkite.com/materialize/test/builds/83401#018ff2fc-8d73-4f4d-8137-d6aa7a9e4a65

I've now tried to temporarily remove Aru's commit that upgrades Hugo to see if that is the reason or my commit.

[ggevay]

"Lint docs" has now passed: https://buildkite.com/materialize/test/builds/83403#018ff300-cc6b-47b9-91bf-af9b01e0c43b
So it seems to be @arusahni's commit from that I cherry-picked earlier which failed the linting. I guess that could be worked on in a separate PR, independently from this one.

[arusahni]

My recollection of that PR is coming back. The Hugo upgrade brings about a change in how it computes URLs. Marta and I chatted about this and decided we probably should go for the workaround described here as the cross reference syntax isn't desirable for our docs.

[morsapaes]

I think there was a mistake when merging the RETAIN HISTORY documentation, because this should use a generic diagram for WITH options which doesn't spell out the options you can use in the diagram itself, but just points out the generic syntax:

The options are then laid out in the respective configuration option table:

We should also include examples for each configuration option since these diagrams are impossible to read, anyway.

---

I'll push up a fix. Pinged @chaas because this is an issue in a lot of reference pages, and we should patch it more generally.

[ggevay]

Ok, this makes a lot of sense! Thank you!

[ggevay]

Btw. are the simplifications compared to the generic WITH option diagram from your above comment intentional? There is only WITH with_options on the diagram now, which doesn't show the parenthesis from the WITH (...) and doesn't show that there should be a comma between the options.