Description

Please provide a clear and concise description of the documentation changes you're proposing in this PR.

• docs/howto/quick-start.md: Remove extra space before colon
• docs/howto/contributing.md: Fix preposition 'ready to' → 'ready for'
• docs/reference/language/syntax.md: Add proper heading format for 'Lambdas'
• docs/reference/tooling/doctor.md: Fix grammar 'they'll be' → 'there will be'
• docs/juvix-packages.md: Add missing word 'make sure' and fix sentence structure
• docs/reference/judoc.md: Remove duplicate word 'have have' → 'have'
• docs/reference/language/modules.md: Fix grammar 'another modules' → 'other modules'
• docs/tutorials/learn.juvix.md: Fix typo 'freatures' → 'features'

Related Issue: # (issue number, if applicable)

N/A

Checklist

• My writing follows the style guidelines of this project.
• I have checked for and corrected any spelling or grammar errors.
• I have performed a self-review of my own writing.
• I have made corresponding changes to existing documentation.
• My changes generate no new warnings or errors using make pre-commit.
• [X ] If I have added or modified a code example, I have tested that the example
  compiles and runs as expected with the latest version of Juvix.

Additional Information

Please provide any additional context or information about the proposed documentation changes here.