Fix public doc linting issues

[flin-8]

Fixes MD-1770: Fix broken CLI docs update workflow linting

The generated docs PR: https://github.com/OctopusDeploy/docs/pull/3109/changes

[flin-8]

MD040 fenced-code-language - Fenced code blocks should have a language specified

[flin-8]

MD047 single-trailing-newline - Files should end with a single newline character

[flin-8]

MD012 no-multiple-blanks - Multiple consecutive blank lines

[flin-8]

MD014 - Dollar signs used before commands without showing output

[flin-8]

MD014 commands-show-output - Dollar signs used before commands without showing output

[flin-8]

@zentron if we think it's important to keep the $ at the front, then we can override the linting rule

[zentron]

Scanning through the changes it all looks reasonable, im assuming the format must have changed at some point since it was last generated. 🤷

[NickJosevski]

Picking up on the suggestion to automate the docs update — worth noting the workflow already runs on v* tag pushes (see .github/workflows/generate-docs.yml), so docs do regenerate on every release. The gap is between releases, where they can drift.

Recommendation: add push-to-main with a path filter, plus an empty-diff guard so we don't open no-op PRs. Preferable to a schedule: because it catches doc-affecting changes promptly and avoids running CI when nothing relevant changed.

Trigger:

on:
  workflow_dispatch:
  push:
    branches:
      - main
    tags:
      - 'v*'
    paths:
      - 'cmd/gen-docs/**'
      - 'pkg/cmd/**'
      - 'go.mod'
      - 'go.sum'
      - '.github/workflows/generate-docs.yml'

Then a Check for docs changes step after Generate cli docs that runs git status --porcelain in the docs checkout, sets a changed output, and gates the Commit / Push / Create PR steps on if: steps.docs-diff.outputs.changed == 'true'.

A couple of notes:

• GitHub does not apply paths filters to tag pushes, so the existing release behaviour is preserved.
• The branch name uses a timestamp (enh-cliupdate-octopus-$(date ...)), so frequent merges could pile up open PRs in the docs repo. If that becomes noisy a follow-up could reuse a rolling branch and update the existing PR.

A schedule: (e.g. weekly) is a fine fallback if we'd rather decouple from commit cadence, but it'll still need the same empty-diff guard and will lag merges by up to a week.