Update `/learn/what_is_meilisearch/features.md`

[maryamsulemani97]

The Features page is outdated but has a ton of views as it is linked to the landing page.

[dichotommy]

In addition to being out of date, "placeholder search" is woefully out of place there. That's more of a functionality than a feature. It's certainly not making or breaking anyone's decision to pick up Meilisearch.

[maryamsulemani97]

Update the page to add missing features like geosearch and multitenancy