Here are some additional things for you to explore to make your search more robust:
If you enter nothing in the search field, all the pages come back in the results. Modify the code to handle blank searches.
Some of the content of your pages is hidden in front matter. For example, your project pages contain technology used, which you might want to see in your searches. Explore how you can include this data in addition to the title and body content.
Review the Lunr documentation to explore how to create a serialized search index instead of creating one on the client. This will require additional processing when you publish your site, but it will speed things up substantially if you have a lot of content.
Explore other search options like Algolia and see how they stack up compared to Lunr.