refactor: split template helpers and slug utils out of markdown.go

[Caesarsage]

Pure relocation; no behavior change. Tests pass without golden updates.

• New template_helpers.go holds the resource.tmpl parse block + escape, hugoRef, and their regex vars.
• Slug helpers (anchor, kebabCase, kebabName, groupVersionString, operationSlug, constValueFor) move into the existing util.go.
• markdown.go drops the moved symbols + now-unused imports.

markdown.go had grown to ~950 lines mixing view-model, writer methods, slug helpers, and template primitives. The extraction lets each file have one concern.

Sets up cleaner ground for the upcoming #440 PRs.

[kubernetes-prow]

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[lavishpal]

Only wanna understand your intention that why is template_helpers.go a separate file instead of merging into util.go and  also escape() is in template_helpers.go but it's a pure string transform, not template-specific. The template FuncMap could reference it from util.go

[lavishpal]

operationSlug and kebabCase have identical implementations. is keeping them separate intentional to allow independent divergence later, or should operationSlug just assign to kebabCase

[Caesarsage]

Only wanna understand your intention that why is template_helpers.go a separate file instead of merging into util.go and  also escape() is in template_helpers.go but it's a pure string transform, not template-specific. The template FuncMap could reference it from util.go

Only wanna understand your intention that why is template_helpers.go a separate file instead of merging into util.go and  also escape() is in template_helpers.go but it's a pure string transform, not template-specific. The template FuncMap could reference it from util.go

Two design choices, each with trade-offs:

On the separate file: template_helpers.go holds the template specific functions registers. They're tightly coupled, anyone wanting to know "what helpers does the template have access to" reads one file end-to-end. Folding into util.go would mix template parsing with the existing PrintInfo diagnostic and slug helpers, three unrelated concerns in one file.

On escape() placement: you're right that it's a pure string transform. So are hugoRef, mdCell, hugoShortcode, and dict, all pure functions whose only caller is the FuncMap. I grouped them with the parse block so the boundary is obvious: "these exist to support the template, reached by these registered names." Moving escape alone to util.go would split the group across files.

[lavishpal]

Make sense.
/lgtm