Prevent redundant H1 titles causing rendering issues with DocItemContent theme

[patrikbraborec]

When using "redundant" titles in documentation, the new DocItemContent theme that handles LLM buttons renders titles in a messy way. This occurs because of how Docusaurus handles titles internally.

Impact

• Messy rendering of titles when LLM buttons are present
• Inconsistent title display across documentation
• Potential for recurring bugs

Proposed Solution

• Option 1: Handle at theme level (DocItemContent) by some useEffectLayout cleaning
• Option 2: Enforce through linter rules

[TC-MO]

I think this can be handled better through option 2, we can create Vale rule to catch H1 and treat it as error, I can tinker with it a bit and see what I come up with

[TC-MO]

#1890 This should prevent future H1's from happening, I'll also run the linter on our docs repo and remove all redundant H1's from fiels that might hide in Academy (and any other place for that matter ¯_(ツ)_/¯)