fix: address PR #754 review feedback - validation, grammar, and formatting

[Copilot]

Description

Addresses review feedback from PR #754 on modal radio/checkbox components. Key fixes:

• Validation bug: Removed ComponentType.Checkbox from modal validation in two locations:
  • DiscordApiClient.cs: Removed from top-level modal component validation
  • DisCatSharpBuilder.cs: Removed from modal-only component types set
  • Checkboxes must be children of DiscordLabelComponent per Discord API requirements, not standalone modal components
• Grammar: Fixed "then" → "than" in error messages
• Documentation: Updated SubComponentType to reflect all attachable component types, not just text input and select. Added clarifying note about Checkbox component usage restrictions.
• Consistency: Fixed XML doc formatting (tab/space inconsistencies) and indentation (spaces → tabs in converter)
• Default value: Changed MinimumValues default from 1 to 0 in DiscordCheckboxGroupComponent to align with validation logic

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

• Solution builds successfully with no warnings
• Code review passes with no issues
• Validation logic verified to prevent invalid component configurations in both builders

Test Configuration:

• .NET SDK: 8.0, 9.0, 10.0
• Build configuration: Release

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules

@Aiko-IT-Systems/discatsharp

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[Lulalaby]

@copilot you still need to address #754 (review)

[Copilot]

@copilot you still need to address #754 (review)

Addressed the sentry review in commit f3d6ff5. Removed ComponentType.Checkbox from s_modalOnlyComponentTypes in DisCatSharpBuilder.cs. Checkboxes are now correctly allowed only as children of DiscordLabelComponent, not as top-level modal components. The validation logic in DiscordApiClient.cs was already fixed in commit 5221ce2.