Repository: traefik/traefik (language: go)

Issue:
Include caveat in documentation that `PathPrefix` matches loosely
### Welcome!

- [X] Yes, I've searched similar issues on [GitHub](https://github.com/traefik/traefik/issues) and didn't find any.
- [X] Yes, I've searched similar issues on the [Traefik community forum](https://community.traefik.io) and didn't find any.

### What did you expect to see?

It seems that `PathPrefix` matches exact prefixes, i.e. without taking into consideration `/` as special separator characters.

Example: ```PathPrefix(`/products`)``` matches all of the following paths:

- ✅ `/products`
- ✅ `/products/shoes`
- ✅ `/products/shirts`
- ⚠️ `/productsforsale`
- ⚠️ `/productsforsale/shoes`

The last two I found surprising, regarding the examples given in the documentation. I could not find anything to say that this was intended behavior but I would suggest to include this as explicit caveat in the docs:

> Use a `*Prefix*` matcher if your service listens on a particular base path but also serves requests on sub-paths. For instance, `PathPrefix: /products` would match `/products` but also `/products/shoes` and `/products/shirts`, **as well as `/productsforsale`**. Since the path is forwarded as-is, your service is expected to listen on `/products`.

Traefik version: `v2.9.4`


Discussion / hints:

Fix patch:
diff --git a/docs/content/routing/routers/index.md b/docs/content/routing/routers/index.md
index 3a5045a27e..537e81ee1a 100644
--- a/docs/content/routing/routers/index.md
+++ b/docs/content/routing/routers/index.md
@@ -276,10 +276,11 @@ The table below lists all the available matchers:
 
 !!! info "Path Vs PathPrefix"
 
-    Use `Path` if your service listens on the exact path only. For instance, `Path: /products` would match `/products` but not `/products/shoes`.
+    Use `Path` if your service listens on the exact path only. For instance, ```Path(`/products`)``` would match `/products` but not `/products/shoes`.
 
     Use a `*Prefix*` matcher if your service listens on a particular base path but also serves requests on sub-paths.
-    For instance, `PathPrefix: /products` would match `/products` but also `/products/shoes` and `/products/shirts`.
+    For instance, ```PathPrefix(`/products`)``` would match `/products` and `/products/shoes`,
+    as well as `/productsforsale`, and `/productsforsale/shoes`.
     Since the path is forwarded as-is, your service is expected to listen on `/products`.
 
 !!! info "ClientIP matcher"


Test patch: