docs: fix install link for Declarative Mode (#13428)

* docs: update install link for Declarative Mode

The current link: `./library/installation` returns a `404`.

The new link: `./declarative/installation` correctly routes to the installation guide for Declarative mode.

* chore: sign CLA by adding username to `contributors.yml`

Author: pruszel

contributors.yml

@@ -269,6 +269,7 @@
 - printfn
 - promet99
 - proshunsuke
+- pruszel
 - pwdcd
 - pyitphyoaung
 - refusado

docs/start/modes.md

@@ -117,7 +117,7 @@ Every mode supports any architecture and deployment target, so the question isn'
 - have a data layer that either skips pending states (like local first, background data replication/sync) or has its own abstractions for them
 - are coming from Create React App (you may want to consider framework mode though)
 
-[→ Get Started with Declarative Mode](./library/installation).
+[→ Get Started with Declarative Mode](./declarative/installation).
 
 ## API + Mode Availability Table