add blog post "OpenSearch in Hopsworks" + Authors

[MagicLex]

Description

Add blog post "OpenSearch in Hopsworks" + Authors

Issues Resolved

[List any issues this PR will resolve]

Check List

• Commits are signed per the DCO using --signoff

By submitting this pull request, I confirm that my contribution is made under the terms of the BSD-3-Clause License.

[smacrakis]

Line 50 should be removed ("div>").
The section "Enabling RAG for LLMs with OpenSearch" should mention how OpenSearch is a feature-complete search solution, offering not just vector search but also other, complementary technologies.
As a general rule, semantic search should be used as part of a hybrid search to get the best results -- after all, if the R phase of RAG doesn't return a result, the G phase can't use it.

[MagicLex]

Thank you for your feedback.

• Removed the stray "div>" tag.
• Added information about OpenSearch's potential for hybrid search in RAG applications.
• Kept the description general to avoid overstating our current implementation in Hopsworks.