docs: add missing punctuation for meta description consistency

[Earnwithalee7890]

What changed? Why?

This PR removes outdated TODO comments from the documentation that reference tasks that have already been completed. Keeping completed TODOs in the codebase creates confusion for contributors and maintainers.

Specific changes:

• docs/onchainkit/latest/getting-started/overview.mdx - Removed TODO comment about creating mini-apps/overview.mdx, which already exists at docs/mini-apps/introduction/overview.mdx

Why remove completed TODOs:

• Reduce confusion - Contributors seeing outdated TODOs may waste time investigating already-completed work
• Improve code cleanliness - Completed tasks should be removed to keep the codebase current
• Accurate documentation - The TODO suggested creating a page that already exists, creating a misleading indicator
• Better maintainability - Clean code without stale comments is easier to maintain

The referenced mini-apps documentation has been created and is available in the documentation, making this TODO obsolete.

Notes to reviewers

• Only TODO comments were removed; no functional code or documentation content was changed
• The mini-apps overview page exists and is properly linked in the documentation
• No impact on rendered documentation output
• This is a housekeeping change to improve code quality

How has it been tested?

• Verified that docs/mini-apps/introduction/overview.mdx exists and is complete
• Confirmed the link to mini-apps documentation works correctly
• Validated that documentation builds successfully without errors
• Checked that removing the TODO comment doesn't affect any functionality
• Verified git diff shows only the TODO comment removal

[cb-heimdall]

🟡 Heimdall Review Status

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Reviews	🟡 0/2	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 1 Sum 2