[docs] Document stable channel nuget.config behavior for aspire new and aspire update

[aspire-repo-bot]

Documents changes from microsoft/aspire#18211 by @JamesNK.

Targeting release/13.5 based on the source PR milestone 13.5 (exact_match).

Why this PR is needed

PR microsoft/aspire#18211 changed the behavior of aspire new and aspire update: when using the stable channel (the default for stable CLI builds), these commands no longer create a project-level nuget.config file. Previously, they always created one. Since nuget.org is already the default NuGet source, the file added no value for stable-channel users. Non-stable channels (staging, daily) still create nuget.config with source mappings for their package feeds. If an existing nuget.config is present when using the stable channel, it is still updated to clean up stale feed entries.

The command reference docs for aspire new and aspire update needed updating to accurately describe this channel-specific behavior, and the What's New 13.5 page needed a mention.

Changes

• src/frontend/src/content/docs/reference/cli/commands/aspire-new.mdx — Added a paragraph to the --channel option description explaining that non-stable channels create a nuget.config with source mappings, while the stable channel does not.
• src/frontend/src/content/docs/reference/cli/commands/aspire-update.mdx — Added a paragraph to the --channel option description clarifying nuget.config creation/update behavior per channel: non-stable creates/updates it, stable skips creation but still cleans up existing configs.
• src/frontend/src/content/docs/whats-new/aspire-13-5.mdx — Added a bullet in the CLI improvements section noting the stable channel nuget.config change.

All three files were updated, not newly created.

Generated by PR Documentation Check for issue #18211 · 2.5K AIC · ⌖ 21.5 AIC · ⊞ 45.2K · ◷

---

Note

This was originally intended as a pull request, but the git push operation failed.

Workflow Run: View run details and download bundle artifact

The bundle file is available in the agent artifact in the workflow run linked above.

To create a pull request with the changes:

# Download the artifact from the workflow run
gh run download 27587483449 -n agent -D /tmp/agent-27587483449

# Fetch the bundle into a temporary ref, then update the local branch
git fetch /tmp/agent-27587483449/aw-microsoft-aspire.dev-docs-18211-stable-channel-nuget-config.bundle refs/heads/docs/18211-stable-channel-nuget-config:refs/bundles/create-pr-docs-18211-stable-channel-nuget-config-cd4d8e660becdc32-3180359d
git update-ref refs/heads/docs/18211-stable-channel-nuget-config-cd4d8e660becdc32 refs/bundles/create-pr-docs-18211-stable-channel-nuget-config-cd4d8e660becdc32-3180359d
git checkout docs/18211-stable-channel-nuget-config-cd4d8e660becdc32
# Ensure the working tree matches the updated branch
git reset --hard
# Remove the temporary bundle ref
git update-ref -d refs/bundles/create-pr-docs-18211-stable-channel-nuget-config-cd4d8e660becdc32-3180359d

# Push the branch to origin
git push origin docs/18211-stable-channel-nuget-config-cd4d8e660becdc32

# Create the pull request
gh pr create --title '[docs] Document stable channel nuget.config behavior for aspire new and aspire update' --base release/13.5 --head docs/18211-stable-channel-nuget-config-cd4d8e660becdc32 --repo microsoft/aspire.dev