docs: note that s3fs template works with any S3-compatible provider

[davidmyriel]

Summary

Adds a short "Other S3-compatible providers" section at the end of docs/sandbox/connect-bucket.mdx noting that the existing s3fs setup generalizes to any S3-compatible object storage provider via the -o url= flag already demonstrated in the Cloudflare R2 example.

Names Tigris, MinIO, and Backblaze B2 as examples so readers searching for those specifically can find confirmation that the existing template works for them, without adding a dedicated section per provider.

Why

The doc currently has per-provider sections for GCS, Amazon S3, and Cloudflare R2. The R2 section already implicitly teaches the generic pattern (override endpoint with -o url=), but a reader looking for any other provider has to infer that it applies to them. A four-line note makes that explicit and avoids future per-provider section sprawl.

Changes

• 1 file changed, 4 insertions, 0 deletions
• docs/sandbox/connect-bucket.mdx: new short section at the end, no new code blocks, points back to the existing R2 example