docs: remove redundant "the" from SDS readme

[stew-r]

Description: a minor tweak to the SDS readme which removes a redundant word
Risk Level: low (docs)
Testing: none
Docs Changes: N/A
Release Notes: not user or extension developer impacting

[snowp]

Can you fix DCO? https://github.com/envoyproxy/envoy/blob/master/CONTRIBUTING.md#fixing-dco

[stew-r]

Can I do this from the GitHub UI?

[dio]

@stew-r We're not aware of it. And, re: the fix, can you find similar issues to this?

[stew-r]

Sorry, I thought this would be an easy/quick fix. I can revert if there isn't a straightforward way to incorporate this small docs change.

[stale]

This pull request has been automatically marked as stale because it has not had activity in the last 7 days. It will be closed in 7 days if no further activity occurs. Please feel free to give a status update now, ping for review, or re-open when it's ready. Thank you for your contributions!

[stew-r]

I'm still interested in making this (and future) improvements to docs. It doesn't seem like it should be hard to make a minor text change. Please let me know if there's a straightforward way to get that done.

[dio]

@stew-r Sorry that DCO is required. A related issue, re: from GitHub UI: todogroup/gh-issues#50.

[stew-r]

Got it. Thanks for following up -- that's a shame. Closing this PR.