use remote_include for logsinks.md and logformats.md

[taroface]

Some syntax in the following docs is not rendered correctly on the public site:

• https://github.com/cockroachdb/cockroach/blob/master/docs/generated/logformats.md
• https://github.com/cockroachdb/cockroach/blob/master/docs/generated/logsinks.md

For this reason, I manually included this content in #10273. The formatting syntax should be fixed on cockroach so that we can rely on using remote_include for these docs.