[CI] Fix Netlify site-build config for Docsy and example sites

[chalin]

There are a few issues with both the main website and the example-site build config. For example, both had this warning:

I've also adjusted the branch build & deploy settings. Not that it mattered much, but the example site still had master as a target branch to build.

[chalin]

• Docsy site: cleared cache, rebuilt and deployed successfully, see https://app.netlify.com/sites/docsydocs/deploys/670805beb3ea2331b2ebd391
• Example site: cleared cache, rebuilt and deployed successfully, see https://app.netlify.com/sites/goldydocs/deploys/6708054bb3ea233250ebcfd7

Done.