Update branding from ".NET Aspire Community Toolkit" to "Aspire Community Toolkit"

[Copilot]

Closes #<ISSUE_NUMBER>

Updates repository branding per updated guidelines: ".NET Aspire Community Toolkit" → "Aspire Community Toolkit"

Changes

• Documentation: Updated README.md, CONTRIBUTING.md, FAQ, versioning, diagnostics, and integration creation guides
• Configuration: Updated copilot-instructions.md and workflow signing descriptions
• README simplifications:
  • Changed "developing with .NET Aspire" to "developing with Aspire"
  • Changed link text from "[.NET Aspire]" to "[Aspire]"
  • Changed "our amazing .NET community" to "our amazing Aspire community"
• Grammar fix: "A .NET Aspire" → "An Aspire" in Flagd integration description

All references to ".NET Aspire" (the framework) remain unchanged—only the toolkit name and related references were updated for consistency with the new branding.

PR Checklist

• Created a feature/dev branch in your fork (vs. submitting directly from a commit on main)
• Based off latest main branch of toolkit
• PR doesn't include merge commits (always rebase on top of our main, if needed)
• New integration
  • Docs are written
  • Added description of major feature to project description for NuGet package (4000 total character limit, so don't push entire description over that)
• Tests for the changes have been added (for bug fixes / features) (if applicable)
• Contains NO breaking changes
• Every new API (including internal ones) has full XML docs
• Code follows all style conventions

Other information

9 files updated across documentation and workflows. No functional changes—purely textual branding updates for consistency.

Original prompt

Update the README.md to no longer call it the .NET Aspire Community Toolkit, just the Aspire Community Toolkit as per the updated branding.

If there would be some ambiguity in the context by remove .NET replace it with Aspire.

---

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

[Copilot]

Pull Request Overview

This PR updates the repository branding from ".NET Aspire Community Toolkit" to "Aspire Community Toolkit" per updated branding guidelines, with no functional changes.

• Updated all references to the toolkit name across documentation and configuration files
• Corrected grammar from "A .NET Aspire" to "An Aspire" for proper article usage
• Simplified references to "developing with .NET Aspire" → "developing with Aspire" and "our amazing .NET community" → "our amazing Aspire community"

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
README.md	Updated main heading, toolkit description, and table entries; fixed article grammar for Flagd integration
CONTRIBUTING.md	Updated all references to the toolkit name in contribution guidelines
docs/faq.md	Updated toolkit name in FAQ answers and descriptions
docs/diagnostics.md	Updated toolkit name in diagnostics documentation header and content
docs/create-integration.md	Updated toolkit name in integration creation guide
docs/versioning.md	Updated toolkit name in versioning overview and release process description
.github/copilot-instructions.md	Updated toolkit name in Copilot coding instructions header
.github/workflows/dotnet-release.yml	Updated package signing description parameter
.github/workflows/dotnet-main.yml	Updated package signing description parameter