feat: bring in CI checks for documentation

[lucaaamaral]

Describe the problem

The magma/magma-documentation lacks proper CI routines to check sanity of documents introduced.

Description

This should be triggered when a PR is opened or after merge.

Additional context

Some of those checks already exist in magma/magma.

Describe your idea

Desired verifications on PRs:

• Markdown lint.
• Markdown files not referenced by docussaurus.
• Markdown files updated in one language and not others.
  • The action to take on that is to open an issue after the merge to main to update the other files.

Additional context

Desired timelines

[lucaaamaral]

Both magma/magma#15152 and magma/magma#15604 might have useful implementation on that regard.

[lucaaamaral]

Desired checks:

• Markdown lint (super-linter might implement lints for multiple languages in a single workflow)
• Markdown FrontMatter verification - Docussaurus requires this information to serve the file
• Docussaurus sanity check - a way to assure Docussaurus will be able to run after changes.

Useful links:

• docusaurus-builddeploy-action
• Current Magma lint workflow
• Current Magma Doccusaurus workflow