docs: align documentation wording and Vale linting

[choufraise]

Summary

• Align README, website docs, contributor docs, ADRs, and issue templates with current wording.
• Add Vale coverage for MDX docs and project-specific vocabulary.
• Exclude generated references and code fragments where Vale creates stale/noisy findings.
• Clarify natsClusterRef fallback documentation and sync generated CRD docs.
• Fix smaller documentation issues, typos, heading style, and public NAuth copy.

Why

This keeps GitHub and nauth.io documentation cleaner, more accurate, and easier to maintain while making Vale useful for real documentation problems instead of project terms and code snippets.

Validation

• git ls-files -z '*.md' '*.mdx' | xargs -0 vale

Commits

• docs: standardize mise task shorthand
• docs: fix ServiceMonitor CRD typo
• docs: clarify natsClusterRef fallback behavior
• docs: normalize public NAuth copy
• docs: lint MDX documentation with Vale
• docs: expand Vale vocabulary for project terms
• docs: fix remaining Vale spelling errors
• docs: normalize project terminology casing
• docs: skip code scopes in Vale
• docs: exclude generated reference docs from Vale
• docs: clear remaining Vale prose errors
• docs: apply Vale preferred wording
• docs: remove future-tense Vale warnings
• docs: remove ellipses from issue templates
• docs: remove first-person example wording
• docs: resolve Oxford comma warnings
• docs: resolve Vale colon-style warnings
• docs: remove collective-pronoun Vale warnings
• docs: align Markdown headings with Vale style
• docs: fix bug report template wording