Search functionality

[robjtede]

Discussed in actix/actix-web#2988

^{Originally posted by samiy803 March 3, 2023}
The documentation on the Actix website is great, but I think it's missing a search feature. This would make it a lot easier to navigate between pages and find the information you're looking for.

[JohnTitor]

Looking at https://docusaurus.io/docs/search, we have some options:

1. Using Algolia DocSearch
   According to the above docs:

   The service is free for any open-source project: just make sure to read the checklist and apply to the DocSearch program.

   That sounds nice, but it feels like too much for our case (I guess it's anything harmful though).

2. Using Local Search
   AFAIK this is the smallest option. We have to find a good plugin but it doesn't add any more external services.

I'm leaning towards the first option if the configuration/setup is simple enough.